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  Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 124 journals)
Showing 1 - 30 of 30 Journals sorted alphabetically
Acta Astronautica     Hybrid Journal   (Followers: 220)
Advances in Aerospace Engineering     Open Access   (Followers: 74)
Advances in Aerospace Science and Technology     Open Access   (Followers: 14)
Advances in Astronautics Science and Technology     Hybrid Journal   (Followers: 2)
Advances in Space Research     Hybrid Journal   (Followers: 295)
Aeronautical Journal, The     Hybrid Journal   (Followers: 9)
Aerospace     Open Access   (Followers: 64)
Aerospace Medicine and Human Performance     Full-text available via subscription   (Followers: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 306)
Aerospace Systems     Hybrid Journal   (Followers: 10)
Aerospace technic and technology     Open Access   (Followers: 7)
Aerotecnica Missili & Spazio : Journal of Aerospace Science, Technologies & Systems     Hybrid Journal   (Followers: 6)
AIAA Journal     Hybrid Journal   (Followers: 1002)
Air Medical Journal     Hybrid Journal   (Followers: 6)
Aircraft Engineering and Aerospace Technology     Hybrid Journal   (Followers: 139)
Artificial Satellites     Open Access   (Followers: 21)
ASTRA Proceedings     Open Access   (Followers: 3)
Astrodynamics     Hybrid Journal   (Followers: 4)
Aviation     Open Access   (Followers: 12)
Aviation in Focus - Journal of Aeronautical Sciences     Open Access   (Followers: 7)
Aviation Psychology and Applied Human Factors     Hybrid Journal   (Followers: 23)
Aviation Week     Full-text available via subscription   (Followers: 411)
Canadian Aeronautics and Space Journal     Full-text available via subscription   (Followers: 31)
CEAS Aeronautical Journal     Hybrid Journal   (Followers: 30)
Chinese Journal of Aeronautics     Open Access   (Followers: 19)
Ciencia y Poder Aéreo     Open Access   (Followers: 3)
Civil Aviation High Technologies     Open Access   (Followers: 6)
Control Systems     Hybrid Journal   (Followers: 235)
Cosmic Research     Hybrid Journal   (Followers: 5)
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 25)
Fatigue of Aircraft Structures     Open Access   (Followers: 21)
Frontiers in Aerospace Engineering     Open Access   (Followers: 20)
Frontiers in Astronomy and Space Sciences     Open Access   (Followers: 15)
Gyroscopy and Navigation     Hybrid Journal   (Followers: 177)
IEEE Aerospace and Electronic Systems Magazine     Full-text available via subscription   (Followers: 251)
IEEE Journal on Miniaturization for Air and Space Systems     Hybrid Journal   (Followers: 2)
IEEE Transactions on Aerospace and Electronic Systems     Hybrid Journal   (Followers: 281)
IEEE Transactions on Circuits and Systems I: Regular Papers     Hybrid Journal   (Followers: 43)
International Journal of Aeroacoustics     Hybrid Journal   (Followers: 37)
International Journal of Aerodynamics     Hybrid Journal   (Followers: 46)
International Journal of Aeronautical and Space Sciences     Hybrid Journal   (Followers: 4)
International Journal of Aerospace Engineering     Open Access   (Followers: 86)
International Journal of Aerospace Innovations     Full-text available via subscription   (Followers: 23)
International Journal of Aerospace Psychology     Hybrid Journal   (Followers: 22)
International Journal of Aerospace Sciences     Open Access   (Followers: 36)
International Journal of Applied Geospatial Research     Hybrid Journal   (Followers: 7)
International Journal of Aviation Management     Hybrid Journal   (Followers: 5)
International Journal of Aviation Technology, Engineering and Management     Full-text available via subscription   (Followers: 8)
International Journal of Aviation, Aeronautics, and Aerospace     Open Access   (Followers: 9)
International Journal of Crashworthiness     Hybrid Journal   (Followers: 10)
International Journal of Micro Air Vehicles     Open Access   (Followers: 11)
International Journal of Satellite Communications Policy and Management     Hybrid Journal   (Followers: 15)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 13)
International Journal of Space Structures     Full-text available via subscription   (Followers: 19)
International Journal of Space Technology Management and Innovation     Full-text available via subscription   (Followers: 11)
International Journal of Sustainable Aviation     Hybrid Journal   (Followers: 5)
Investigación Pecuaria     Open Access   (Followers: 1)
Journal of Aerodynamics     Open Access   (Followers: 27)
Journal of Aeronautical Materials     Open Access   (Followers: 10)
Journal of Aerospace Engineering     Full-text available via subscription   (Followers: 66)
Journal of Aerospace Engineering & Technology     Full-text available via subscription   (Followers: 22)
Journal of Aerospace Information Systems     Hybrid Journal   (Followers: 27)
Journal of Aerospace Information Systems     Hybrid Journal   (Followers: 57)
Journal of Aerospace Technology and Management     Open Access   (Followers: 10)
Journal of Aircraft     Hybrid Journal   (Followers: 263)
Journal of Aircraft and Spacecraft Technology     Open Access   (Followers: 15)
Journal of Airline and Airport Management     Open Access   (Followers: 11)
Journal of Astrobiology & Outreach     Open Access   (Followers: 5)
Journal of Aviation Technology and Engineering     Open Access   (Followers: 10)
Journal of Aviation/Aerospace Education & Research     Open Access   (Followers: 2)
Journal of Engineering and Technological Sciences     Open Access   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 165)
Journal of KONBiN     Open Access   (Followers: 4)
Journal of Navigation     Hybrid Journal   (Followers: 176)
Journal of Propulsion and Power     Hybrid Journal   (Followers: 569)
Journal of Space Safety Engineering     Hybrid Journal   (Followers: 8)
Journal of Space Weather and Space Climate     Open Access   (Followers: 30)
Journal of Spacecraft and Rockets     Hybrid Journal   (Followers: 702)
Journal of Spatial Science     Hybrid Journal   (Followers: 4)
Journal of the American Helicopter Society     Full-text available via subscription   (Followers: 9)
Journal of the Astronautical Sciences     Hybrid Journal   (Followers: 11)
Journal of the Australasian Society of Aerospace Medicine     Open Access   (Followers: 3)
Journal of Wind Engineering and Industrial Aerodynamics     Hybrid Journal   (Followers: 21)
Life Sciences in Space Research     Hybrid Journal   (Followers: 5)
MAD - Magazine of Aviation Development     Open Access   (Followers: 3)
Mekanika : Jurnal Teknik Mesin i     Open Access  
Microgravity Science and Technology     Hybrid Journal   (Followers: 3)
New Space     Hybrid Journal   (Followers: 6)
Nonlinear Dynamics     Hybrid Journal   (Followers: 19)
npj Microgravity     Open Access   (Followers: 3)
Open Aerospace Engineering Journal     Open Access   (Followers: 4)
Perspectives of Earth and Space Scientists i     Open Access   (Followers: 1)
Population Space and Place     Hybrid Journal   (Followers: 10)
Problemy Mechatroniki. Uzbrojenie, lotnictwo, inżynieria bezpieczeństwa / Problems of Mechatronics. Armament, Aviation, Safety Engineering     Open Access   (Followers: 3)
Proceedings of the Human Factors and Ergonomics Society Annual Meeting     Hybrid Journal   (Followers: 16)
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering     Hybrid Journal   (Followers: 42)
Progress in Aerospace Sciences     Full-text available via subscription   (Followers: 82)
Propulsion and Power Research     Open Access   (Followers: 89)
REACH - Reviews in Human Space Exploration     Full-text available via subscription   (Followers: 5)
Research & Reviews : Journal of Space Science & Technology     Full-text available via subscription   (Followers: 20)
RocketSTEM     Free   (Followers: 5)
Russian Aeronautics (Iz VUZ)     Hybrid Journal   (Followers: 23)
Science and Education : Scientific Publication of BMSTU     Open Access   (Followers: 1)
Space and Polity     Hybrid Journal   (Followers: 6)
Space Policy     Hybrid Journal   (Followers: 30)
Space Research Today     Full-text available via subscription   (Followers: 43)
Space Safety Magazine     Free   (Followers: 50)
Space Science International     Open Access   (Followers: 117)
Space Science Reviews     Hybrid Journal   (Followers: 92)
SpaceNews     Free   (Followers: 779)
Spatial Information Research     Hybrid Journal   (Followers: 1)
Transactions on Aerospace Research     Open Access   (Followers: 1)
Transport and Aerospace Engineering     Open Access   (Followers: 4)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 7)
Unmanned Systems     Hybrid Journal   (Followers: 4)
Xibei Gongye Daxue Xuebao / Journal of Northwestern Polytechnical University     Open Access  
Вісник Національного Авіаційного Університету     Open Access   (Followers: 1)

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Journal Cover
Aircraft Engineering and Aerospace Technology
Journal Prestige (SJR): 0.354
Citation Impact (citeScore): 1
Number of Followers: 139  
 
Hybrid Journal Hybrid journal   * Containing 4 Open Access Open Access article(s) in this issue *
ISSN (Print) 0002-2667 - ISSN (Online) 2059-9366
Published by Emerald Homepage  [360 journals]
  • The fuzzy PD control for combined energy and attitude control system

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      Authors: Sohaib Aslam , Yew-Chung Chak , Mujtaba Hussain Jaffery , Renuganth Varatharajoo
      Abstract: The satellite pointing accuracy plays a crucial role in ensuring a successful satellite mission itself. Therefore, this paper aims to enhance the attitude pointing accuracy of the combined energy and attitude control system (CEACS) in a satellite in the presence of external disturbance torques through a robust controller, which can produce high pointing accuracies with smaller control torques. To improve the CEACS attitude pointing accuracy, a maiden fuzzy proportional derivative (PD)-based CEACS architecture is proposed. The mathematical models along with its numerical treatments of the fuzzy PD-based CEACS attitude control architecture are presented. In addition, a comparison between the PD and fuzzy PD controllers in terms of the CEACS pointing accuracies and control torques is provided. Numerical results show that the fuzzy PD controller produces a considerable CEACS pointing accuracy improvement for a lower control torque compartment. CEACS has gained a renew interest because of significant increase in the projected onboard power requirements for future space missions. Therefore, it is of paramount importance to improve the CEACS pointing accuracy itself with a minimum control torque compartment. In fact, this proposed fuzzy PD controller is shown to be a potential CEACS attitude controller. The fuzzy PD-based CEACS architecture not only provides a better attitude pointing accuracy but also ensures a lower control torque compartment, which corresponds to a lower onboard power consumption.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-19
      DOI: 10.1108/AEAT-05-2021-0144
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • The effects of flap extension time on the fuel burn of commercial aircraft

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      Authors: Ozlem Sahin
      Abstract: This paper aims to investigate the effects of descent time spent with flaps extended on fuel burn (FB) and specific range for five different flight path angles (FPAs) ranging between 2.0° and 4.0° for a commercial aircraft. A large data set of actual flight data (n = 475) of the same type of a frequently used commercial aircraft were investigated by using statistical methods. The result of the comparison of the highest and the lowest FBs of flight profiles for each FPAs present that the fuel saving was achieved by keeping at as a high airspeed as possible and deploying flaps as late as possible, which is in line with the objective of delayed deceleration approaches. From analyzing the flight profiles, it was proven that delaying deceleration and also descending without flaps or with flap over a shorter time resulted in less FB of 101.1, 70.9 and 94.9 kg for FPA 2.5°, FPA 3.0° and FPA 3.5°, respectively. This study differs from prior studies because it focused on the effects of the different vertical profiles on FB. Also, the use of real flight data recorder data in the analysis presents the originality of this study.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-17
      DOI: 10.1108/AEAT-05-2021-0148
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • A vision-aided fuzzy adaptive sliding mode controller for autonomous
           landing of a nonlinear model helicopter on a moving marine platform

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      Authors: Farhad Pakro , Amir Ali Nikkhah
      Abstract: A vision-assisted fuzzy adaptive sliding mode controller is presented in this research and implemented on a nonlinear helicopter model, which is about to land on a moving ship. Stabilization of the dynamics and tracking the landing path are required, at the same time. This study aims to take one step closer to fully autonomous landing, which is a growing trend. An integrated guidance and control is considered for the model helicopter. A fuzzy logic is designed to adaptively choose the best control parameters for the sliding mode controller and solve the challenge of parameter tuning. A self-organizing matrix consisting of fuzzy sliding mode parameters is formed instead of a single parameter with the goal of enhancing controller tracking capability. A simple, precise and fast image recognition system based on OpenCV is used to detect the proper point for descending without getting any special data from the ship and by only using a general “H” sign. The problem is simulated under intense disturbances, while the approach and landing performances are acceptable. Controller performance is compared and validated. Simulation results show the robustness, agility, stability and outperformance of the proposed controller. The novelty of this paper is the designed procedure for using a simple image recognition system in the process of autonomous ship-landing, which does not use any special data sent from the ship. Besides, an improved nonlinear controller is designed for integrated guidance and control in this specific application.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-13
      DOI: 10.1108/AEAT-10-2021-0301
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Potentials of prognostics and health management for polymer electrolyte
           fuel cells in aviation applications

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      Authors: Kathrin Ebner , Lily Koops
      Abstract: A reliable and safe operation of fuel cells (FCs) is imperative for their application in aviation, especially within the main powertrain. Moreover, performance and lifetime requirements for technical and economic viability are demanding compared to their stationary or road transportation counterparts, while the operating conditions are considered challenging. Prognostics and health management (PHM) could represent a powerful tool for enhancing reliability, durability and performance by detecting, predicting and/or mitigating relevant degradation and failure mechanisms. Against this backdrop, the authors consider it of high relevance to obtain an understanding of the effectiveness of PHM approaches for polymer electrolyte fuel cells (PEFCs) for future aircraft applications, which represents the aim of this paper. In this study, the authors first discuss application relevant failure modes, review state-of-the-art PHM approaches and, consecutively, assess the potential of FC control strategies for aviation. Aiming for a tangible, comparable metric for this initial assessment, the authors apply a published remaining useful life prediction method to load profiles for a range of aviation-specific applications. The authors’ analysis shows significant potentials for lifetime improvement by (partial) avoidance of high power operation and rapid load change through control strategies. Tapping into these theoretical potentials, however, requires significant developments in the field of PEFC PHM and a focus on aviation specific degradation and performance testing. The novelty of this study lies in creating an understanding of the potential of avoiding or preventing certain degradation modes by means of PHM in the PEFC specifically in aviation applications.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-12
      DOI: 10.1108/AEAT-01-2022-0020
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Artificial neural network based wing planform aerodynamic optimization

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      Authors: Burak Dam , Tolga Pirasaci , Mustafa Kaya
      Abstract: Environmental and operational restrictions increasingly drive modern aircraft design due to the growing impact of global warming on the ecology. Regulations and industrial measures are being introduced to make air traffic greener, including restrictions and environmental targets for aircraft design that increase aerodynamic efficiency. This study aims to maximize aerodynamic efficiency by identifying optimal values for sweep angle, taper ratio, twist angle and wing incidence angle parameters in wing design while keeping wing area and span constant. Finding optimal wing values by using gradient-based and evolutionary algorithm methods is very time-consuming. Therefore, an artificial neural network-based surrogate model was developed. Computational fluid dynamics (CFD) analyses were carried out by using Reynolds-averaged Navier–Stokes equations to create a properly trained data set using a feedforward neural network. The results showed how a wing could be optimized by using a CFD-based surrogate model. The two optimum results obtained resulted in increases of 10.7397% and 10.65% in the aerodynamic efficiency of the baseline design ONERA M6 wing. The originality of this study lies in the combination of sweep angle, taper ratio, twist angle and wing incidence angle within the scope of wing optimization calculations.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-12
      DOI: 10.1108/AEAT-10-2021-0311
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Effect of turbulence intensity on aerodynamic characteristics of extended
           trailing edge airfoil

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      Authors: E. Livya , S. Nadaraja Pillai
      Abstract: This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence. In this paper, an experimental study on NACA 0020 airfoil with thin extended trailing edge modification of amplitude of h = 0.1c, 0.2c and 0.3c at the Reynolds number of 2.14 × 105 are tested. The research was carried out for an angle of attack ranging from 0° = α = 35° for the turbulence intensity of 0.3%, 3%, 5%, 7% and 12%. From the experimental readings, the surface pressures are scanned using a Scanivalve (MPS2464) pressure scanner for a sampling frequency of 700 Hz. The scanned pressures are converted to aerodynamic force coefficient and the results are combined and discussed. The airfoil with the extended trailing edge will convert the adverse pressure gradient to a plateau pressure zone, indicating the delayed flow separation. The CL value at higher turbulence intensity (TI = 12%) for the extended trailing edge over perform the base airfoil at the post-stall region. The maintenance of flow stability is observed from the spectral graph. A thin elongated trailing edge attached to the conventional airfoil serves as a flow control device by delaying the stall and improving the lift characteristics. Additionally, extending the airfoil's trailing edge helps to manage the performance of the airfoil even at a high level of turbulence. Distinct from existing studies, the presented results reveals how the extended trailing edge attached to the airfoil performs in the turbulence zone ranging from 0.3% to 12% of TI. The displayed pressure distribution explains the need for increasing trailing edge amplitude (h) and its impact on flow behaviour. The observation is that extended trailing edge airfoil bears to maintain the performance even at higher turbulence region.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-09
      DOI: 10.1108/AEAT-12-2021-0382
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Fault detection based on extended state observer and interval observer for
           UAVs

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      Authors: Lijia Cao , Xu Yang , Guoqing Wang , Yang Liu , Yu Hu
      Abstract: The purpose of this paper is to present an actuator fault detection method for unmanned aerial vehicles (UAVs) based on interval observer and extended state observer. The proposed algorithm has very little model dependency. Therefore, a six-degree-of-freedom linear equation of UAVs is first established, and then, combined with actuator failure and external disturbances in flight control, a steering gear model with actuator failure (such as stuck bias and invalidation) is designed. Meanwhile, an extended state observer is designed for fault detection. Moreover, a fault detection scheme based on interval observer is designed by combining fault and disturbances. The method is testified on the extended state observer and the interval observer under the failure of the steering gear and bounded disturbances. The simulation results show that the two types of fault detection schemes designed can successfully detect various types of faults and have high sensitivity. This research paper studies the failure detection scheme of the UAVs’ actuator. The fault detection scheme in this paper has better performance on actuator faults and bounded disturbances than using regular fault detection schemes.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-06
      DOI: 10.1108/AEAT-05-2021-0164
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Semisupervised fault diagnosis of aeroengine based on denoising
           autoencoder and deep belief network

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      Authors: Defeng Lv , Huawei Wang , Changchang Che
      Abstract: The purpose of this study is to analyze the intelligent semisupervised fault diagnosis method of aeroengine. A semisupervised fault diagnosis method based on denoising autoencoder (DAE) and deep belief network (DBN) is proposed for aeroengine. Multiple state parameters of aeroengine with long time series are processed to form high-dimensional fault samples and corresponding fault types are taken as sample labels. DAE is applied for unsupervised learning of fault samples, so as to achieve denoised dimension-reduction features. Subsequently, the extracted features and sample labels are put into DBN for supervised learning. Thus, the semisupervised fault diagnosis of aeroengine can be achieved by the combination of unsupervised learning and supervised learning. The JT9D aeroengine data set and simulated aeroengine data set are applied to test the effectiveness of the proposed method. The result shows that the semisupervised fault diagnosis method of aeroengine based on DAE and DBN has great robustness and can maintain high accuracy of fault diagnosis under noise interference. Compared with other traditional models and separate deep learning model, the proposed method also has lower error and higher accuracy of fault diagnosis. Multiple state parameters with long time series are processed to form high-dimensional fault samples. As a typical unsupervised learning, DAE is used to denoise the fault samples and extract dimension-reduction features for future deep learning. Based on supervised learning, DBN is applied to process the extracted features and fault diagnosis of aeroengine with multiple state parameters can be achieved through the pretraining and reverse fine-tuning of restricted Boltzmann machines.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-05
      DOI: 10.1108/AEAT-10-2020-0234
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Improved radial basis function artificial neural network and exact-time
           extended state observer based non-singular rapid terminal sliding-mode
           control of quadrotor system

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      Authors: Mati Ullah , Chunhui Zhao , Hamid Maqsood
      Abstract: The purpose of this paper is to design a hybrid robust tracking controller based on an improved radial basis function artificial neural network (IRBFANN) and a novel extended-state observer for a quadrotor system with various model and parametric uncertainties and external disturbances to enhance the resiliency of the control system. An IRBFANN is introduced as an adaptive compensator tool for model and parametric uncertainties in the control algorithm of non-singular rapid terminal sliding-mode control (NRTSMC). An exact-time extended state observer (ETESO) augmented with NRTSMC is designed to estimate the unknown exogenous disturbances and ensure fast states convergence while overcoming the singularity issue. The novelty of this work lies in the online updating of weight parameters of the RBFANN algorithm by using a new idea of incorporating an exponential sliding-mode effect, which makes a remarkable effort to make the control protocol adaptive to uncertain model parameters. A comparison of the proposed scheme with other conventional schemes shows its much better performance in the presence of parametric uncertainties and exogenous disturbances. The investigated control strategy presents a robust adaptive law based on IRBFANN with a fast convergence rate and improved estimation accuracy via a novel ETESO. To enhance the safety level and ensure stable flight operations by the quadrotor in the presence of high-order complex disturbances and uncertain environments, it is imperative to devise a robust control law. A new idea of incorporating an exponential sliding-mode effect instead of conventional approaches in the algorithm of the RBFANN is used, which makes the control law resistant to model and parametric uncertainties. The ETESO provides rapid and accurate disturbance estimation results and updates the control law to overcome the performance degradation caused by the disturbances. Simulation results depict the effectiveness of the proposed control strategy.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-02
      DOI: 10.1108/AEAT-06-2021-0189
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Impact of human factors in aircraft accident mitigation and aircraft
           maintenance training needs in post COVID-19 aviation

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      Authors: Karunakaran C.S. , Ashok Babu J.
      Abstract: The purpose of this study is to analyze the effect of human factor training in aircraft maintenance accident mitigation and aircraft safety in post COVID-19 aviation scenarios. The cause of aircraft accidents and details of three decades of selective aircraft maintenance accidents are analyzed to arrive to the significant aviation safety factor. The effect of COVID-19 pandemic and related technological applications to maintain high standards of safety and their applications in aircraft maintenance with respect to the view of human factors are discussed in details. This paper details the overview of the human errors, error mitigation and need of human factor applications in aircraft maintenance industry for safe air travel. The criticality of aircraft maintenance in keeping aircraft in airworthy condition to provide safe air transportation without delay and to support airline economy is discussed in this study. The cause of aircraft accidents and details of three decades of selective aircraft maintenance accidents are analyzed to arrive to the significant aviation safety factor. The effect of COVID-19 pandemic and related technological applications to maintain high standards of safety and their applications in aircraft maintenance with respect to the view of human factors are discussed in details. The route of error mitigation and need of high standard technological training with human factor knowledge, to aircraft maintenance students are analyzed in detail with the opportunity of percentages of error reduction. This study bridges, gained knowledge for aircraft maintenance error mitigation, current accident rates and future training needs for safest air travel through high standard quality maintenance in aircraft and its systems.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-05-02
      DOI: 10.1108/AEAT-10-2021-0300
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Numerical procedure for the simulation of an electro-thermal anti-icing
           system

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      Authors: Antonio Carozza , Francesco Petrosino , Giuseppe Mingione
      Abstract: This study aims to couple two codes, one able to perform icing simulations and another one capable to simulate the performance of an electrothermal anti-icing system in an integrated fashion. The classical tool chain of icing simulation (aerodynamics, water catch and impact, mass and energy surface balance) is coupled to the thermal analysis through the surface substrate and the ice thickness. In the present approach, the ice protection simulation is not decoupled from the ice accretion simulation, but a single computational workflow is considered. A fast approach to simulate advanced anti-icing systems is found in this study. This study shows the validation of present procedure against literature data, both experimental and numerical.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-29
      DOI: 10.1108/AEAT-07-2021-0222
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Fuzzy Bayesian based bow-tie risk assessment of runway overrun: a method
           for airline flight operations

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      Authors: Caner Acarbay , Emre Kiyak
      Abstract: The purpose of this paper is to improve risk assessment processes in airline flight operations by introducing a dynamic risk assessment method. Fuzzy logic and Bayesian network are used together to form a dynamic structure in the analysis. One of the most challenging factors of the analyses in aviation is to get quantitative data. In this study, the fuzzy data quantification technique is used to perform dynamic risk assessment. Dynamic structure in the analysis is obtained by transforming the bow-tie model into a Bayesian network equivalent. In this study, the probability of top-event from fault tree analysis is calculated as 1.51 × 10−6. Effectiveness of the model is measured by comparing the analysis with the safety performance indicator data that reflects past performance of the airlines. If two data are compared with each other, they are at the same order of value, with small difference (0.6 × 10−7). This study proposes a dynamic model to be used in risk assessment processes in airline flight operations. A dynamic model for safety analysis provides real-time, autonomous and faster risk assessment. Moreover, it can help in the decision-making process and reduce airline response time to undesired states, which means that the proposed model can contribute to the efficiency of the risk management process in airline flight operations.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-29
      DOI: 10.1108/AEAT-09-2021-0272
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Aerodynamic study of low Reynolds number airfoil and mini-unmanned aerial
           vehicle in simulated rain environment

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      Authors: Somashekar V. , Immanuel Selwynraj A.
      Abstract: Rainfall is one of the main atmospheric conditions that significantly affect the aerodynamic performance of the low Reynolds number flights. In this paper, the adverse effects of rain on the aerodynamic performance of a two-dimensional (2D) airfoil with a chord-based low Reynolds number of 2 × 105 and the mini-unmanned aerial vehicle (UAV) for various flight conditions, i.e. 0°–40° at Mach number 0.04 were studied numerically. The purpose of this study is to explore the aerodynamic penalties that affect the liquid water content (LWC = 5.33) of the airfoil and UAV performance in rain under different flying conditions. The Eulerian–Lagrangian two-phase flow method is adopted to simulate the rain environment over an airfoil and mini-UAV aerodynamic performances. The Reynolds Averaged Navier–Stokes equations are considered to solve the time-averaged equations of motion for fluid flow. The effect of rainfall on the airfoil and mini-UAV is studied numerically and validated experimentally. For 2D airfoil, the lift and drag coefficients for both numerical and experimental results show a very good correlation at Reynolds number 2 × 105. For three-dimensional (3D) mini-UAV, the lift and drag coefficients for both numerical and experimental results show a very good correlation at Mach number 0.04. The raindrops distribution around the airfoil, premature trailing edge separation, boundary-layer velocity profiles at five different chord positions (i.e. LE, 0.25c, 0.5c, 0.75c and 0.98c) on the upper surface of the airfoil, water film height and the location of rivulet formation on the upper surface of the airfoil are also presented. For 2D airfoil, the recorded maximum variation of the coefficient of lift and lift-to-drag (L/D) ratio is observed to be 5.33% at an 8° and 10.53% at a 4° angle of attack (AOA) between numerical and experimental results under the influence of rainfall effect for LWC = 5.33. The L/D ratio percentage degradation is seen to be 61.9% at an AOA of 0°–2° for the rain environment. For 3D mini-UAV, the recorded maximum variation of the coefficient of lift and L/D ratio are observed to be 2.84% and 4.60% at a 30° stall AOA under the influence of rainfall effect for LWC = 5.33. The numerical results are impressively in agreement with the experimental results. UAV designers will benefit from the findings presented in this paper. This will be also helpful for training the pilots to control the airplanes in a rain environment.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-28
      DOI: 10.1108/AEAT-12-2021-0379
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Development and validation of the multicopter modelling code: a
           physics-based tool for multicopter analysis

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      Authors: David Kofi Oppong , Evans Obu , Timothy Asare , God'sable Sitsofe Koku Aidam
      Abstract: This study aims to present details of the development and validation of the multicopter modelling code (MMC), a tool for the analysis of small-scale multicopters based on flight physics. The development effort involved the study of aircraft dynamics and translating the equations of motion into MATLAB code. The authors also developed several auxiliary functions, so that the tool could trim the aircraft about a steady state, linearize the dynamic equations to produce a model that could be used for control systems design and carry out flight simulation. MMC proved to be of good accuracy, producing results similar to those of other software such as AcuSolve, Overflow and the Rensselaer Multicopter Analysis Code (RMAC), which served as the motivation for this study. The tool presented here provides an alternative to the aforementioned software, which are not freely available, programmed in MATLAB, a language well known to engineers and scientists.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-26
      DOI: 10.1108/AEAT-01-2022-0011
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Cluster selection for load balancing in flying networks using an optimal
           low-energy adaptive clustering hierarchy based on optimization approach

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      Authors: Seyed Salar Sefati , Simona Halunga , Roya Zareh Farkhady
      Abstract: Flying ad hoc networks (FANETs) have a major effect in various areas such as civil projects and smart cities. The facilities of installation and low cost of unmanned aerial vehicles (UAVs) have created a new challenge for researchers. Cluster head (CH) selection and load balancing between the CH are the most critical issues in the FANETs. For CH selection and load balancing in FANETs, this study used efficient clustering to address both problems and overcome these challenges. This paper aims to propose a novel CH selection and load balancing scheme to solve the low energy consumption and low latency in the FANET system. This paper tried to select the CH and load balancing with the help of low-energy adaptive clustering hierarchy (LEACH) algorithm and bat algorithm (BA). Load balancing and CH selection are NP-hard problems, so the metaheuristic algorithms can be the best answer for these issues. In the LEACH algorithm, UAVs randomly generate numerical, and these numbers are sorted according to those values. To use the load balancing, the threshold of CH has to be considered; if the threshold is less than 0.7, the BA starts working and begins to find new CH according to the emitted pulses. The proposed method compares with three algorithms, called bio-inspired clustering scheme FANETs, Grey wolf optimization and ant colony optimization in the NS3 simulator. The proposed algorithm has a good efficiency with respect to the network lifetime, energy consumption and cluster building time. This study aims to extend the UAV group control concepts to include CH selection and load balancing to improve UAV energy consumption and low latency.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-22
      DOI: 10.1108/AEAT-08-2021-0264
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Lip thickness effect on high bypass co-flowing jet mixing

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      Authors: Naren Shankar R. , Ganesan V.G.
      Abstract: The purpose of this study is to analyse numerically and experimentally the effects of lip thickness (LT) and bypass ratio on co-flowing nozzle under subsonic and correctly expanded sonic jet decay at different Mach numbers. Co-flowing jets from co-flowing nozzles of different LTs, 0.2, 1 and 1.5 Dp (where Dp is the primary nozzle exit diameter = 10 mm), with an annular gap of 10 mm at main jet exit Mach numbers 0.6 have been studied experimentally and the other cases have been performed numerically. The co-flowing jet with 2 mm LT was used for comparison. Co-flowing jet axial pitot pressure decay, axial static pressure decay, axial velocity decay, radial velocity decay and streamline velocity contours were analyzed. The results illustrate that the mixing of the co-flowing jet with profound LT is prevalent to the co-flowing jet with 2 mm LT, at all Mach numbers of the current study. Also, the LT of the co-flowing jet has a strong impact on jet mixing. Co-flowing jets with 10 mm and 15 mm LT with a constant co-flow width of 10 mm experience a considerably advanced mixing than co-flowing jets with 2 mm LT and a co-flow width of 10 mm. The application of bypassed co-flow jet is in turbofan engine operates efficiently in modern civil aircraft. All subsonic jets are considered correctly expanded with negligible variation in axial static pressure. However, in the present study, static pressure along the centerline varies sinusoidally up to 9% and 12% above and below atmospheric pressure, respectively, for primary jet exit Mach number 1.0. The sinusoidal variation is less for primary jet exit Mach numbers 0.6 and 0.8 in static pressure decay.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-20
      DOI: 10.1108/AEAT-02-2021-0050
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Fast vibro-acoustic simulation methods of satellite components

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      Authors: Jie Zhang , Weihua Xie , Yakun Wang , Jiang Zhou , Jiacong Yin
      Abstract: This paper aims to fast predict vibration responses of specific locations in the satellite subject to acoustic environment. It proposes a set of vibro-acoustic simulation methods of satellite components to represent their conditions in the whole satellite during the ground tests or launching. This study aims to use vibro-acoustic models of satellite components to replace that of hard modeling and time-consuming whole satellite when only local responses are concerned. This paper adopted experimental and numerical studies, with the latter based on the finite element (FE), statistical energy analysis (SEA) and FE-SEA hybrid theories. The vibro-acoustic model of the whole satellite was built and verified by experimental data. Based on the whole satellite model and experimental results, the fast vibro-acoustic simulation methods of all kinds of typical satellite components were discussed. This paper shows that the models about satellite components not only show high consistency but also reduce 61.6% to 99.8% times compared with the whole satellite model. The recommended fast simulation methods for all kinds of typical satellite components were given in comprehensive consideration of the model accuracy, time required and response accessibility. This paper fulfils an identified need to perform fast vibro-acoustic prediction of the local positions in satellites.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-19
      DOI: 10.1108/AEAT-08-2021-0248
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • CFD-based time-domain aeroelastic simulations of a twin-fudelage aircraft

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      Authors: Xinjiang Wang , Ziqiang Liu , Li Guo , Jinan Lv , Chen Ji
      Abstract: The purpose of this paper is to introduce a novel method to study the flutter coupling mechanism of the twin-fuselage aircraft, which is becoming a popular transportation vehicle recently. A new method of flutter mode indicator is proposed based on the principle of work and power, which is realized through energy accumulation of generalized force work on generalized coordinates, based on which flutter coupling mechanism of the twin-fuselage aircraft is studied using ground vibration test and computational fluid dynamics/computational solid dynamics method. Verification of the proposed flutter mode indicator is provided, by which the flutter mechanism of the twin fuselage is found as the horizontal tail’s torsion coupled with its bending effect and the “frequency drifting” phenomenon of twin-fuselage aircraft is explained logically, highlighting the proposed method in this paper. This paper proposed a new method of flutter mode indicator, which has advantages in flutter modes indexes reliability, clear physical meaning and results normalization. This study found the flutter coupling mechanism of twin-fuselage aircraft, which has important guiding significance to the development of twin-fuselage aircraft.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-19
      DOI: 10.1108/AEAT-08-2021-0261
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Study on cooling inerting of an airborne fuel tank in flight

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      Authors: Guannan Liu , Liqun Wang , Hongming Wang , Long Huang , Hao Peng , Shiyu Feng
      Abstract: This study aims to seek a new economic and environmental protection fuel tank inerting method. The principle that serves as the basis for the cooling inerting process is described, the workflow of the cooling inerting system is designed, the mathematical model of the cooling inerting system is established, and the important performance changes of cooling inerting in the flight package line and the influence of key parameters on it are simulated by using Modelica software. The results show that the cooling inerting system can be turned on to quickly reduce the vapour concentration in the gas phase in the fuel space and reduce the temperature below the flammability limit. Within a certain range of pumping flow, the inerting effect is more obvious when the pumping flow is larger. Simply running the cooling inerting system on the ground can remain the tank in an inert state throughout the flight envelope. However, cooling inerting is suitable for models with fewer internal heat sources. An excessive number of internal heat sources will lead to inerting failure. This study provides theoretical support for the feasibility of cooling inerting. Cooling inerting does not require engine air, and the cooling is mainly accomplished with air, which places a small load on the cooling system and has a much lower cost than the airborne hollow fibre film inerting technology widely used at present. It is a promising new inerting technology.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-18
      DOI: 10.1108/AEAT-08-2021-0263
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Performance analysis of electrical flight control actuation system in a
           commercial transport aircraft

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      Authors: Hamdi Ercan , Mustafa Akın
      Abstract: In more than 100 years of aviation, significant progress has been made in flight control systems. The aircrafts that have entered service for the past ten years tend towards power-by-wire flight control with electrical actuators. The purpose of this study is to analyse the effects of electrical actuation on power consumption, weight and fuel consumption on a commercial transport aircraft. The Airbus A321-200 aircraft was chosen as a case study for analysing the effects of electrical actuation on the flight control actuation system (FCAS) architecture, and Pacelab SysArc software was used for design, modelling and analysis. As alternatives to the existing system, hybrid and all-electric models are built to a set of design guidelines with certain limitations. Compared to the existing FCAS architecture model, 80 kg weight savings in the hybrid FCAS architecture model and 171 kg weight savings in the all-electric FCAS architecture model were observed. In terms of fuel consumption, it has been observed that there is 0.25% fuel savings in the hybrid FCAS architecture model, and 0.48% fuel savings in the all-electric FCAS architecture model compared to the existing FCAS architecture model at 3200 NM. In line with the data obtained from this study, it is predicted that electrical actuation is more preferable in aircraft, considering its positive effects on weight and fuel consumption. In this study, three different models were created: the existing FCAS architecture of a commercial transport aircraft, the hybrid FCAS architecture and the all-electric FCAS architecture. Hybrid and all-electric models are built according to a set of design guidelines, with certain limitations. Then, similar flight missions consisting of the same flight conditions are defined to analyse the effects of power consumption, weight, and fuel consumption comparatively.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-18
      DOI: 10.1108/AEAT-11-2021-0326
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • LES predictions of confinement effect on swirling flow generated by single
           helical axial swirler

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      Authors: Mavuri Rajesh , Sivakumar R.
      Abstract: For higher swirling flows (swirl > 0.5), flow confinement significantly impacts fluid flow, flame stability, flame length and heat transfer, especially when the confinement ratio is less than 9. Past numerical studies on helical axial swirler type systems are limited to non-reacting or reacting flows type Reynolds averaged Navier Stokes closure models, mostly are non-parametric studies. Effects of parametric studies like swirl angle and confinement on the unsteady flow field, either numerical or experimental, are very minimal. The purpose of this paper is to document modeling practices for a large eddy simulation (LES) type grid, predict the confinement effects of a single swirler lean direct injection (LDI) system and validate with literature data. The first part of the paper discusses the approach followed for numerical modelling of LES with the minimum number of cells required across critical sections to capture the spectrum of turbulent energy with good accuracy. The numerical model includes all flow developing sections of the LDI swirler, right from the axial setting chamber to the exit of the flame tube, and its length is effectively modelled to match the experimental data. The computational model predicts unsteady features like vortex breakdown bubble, represented by a strong recirculation zone anchored downstream of the fuel nozzle. It is interesting to note that the LES is effective in predicting the secondary recirculation zones in the divergent section as well as at the corners of the tube wall. The predictions of a single helical axial swirler with a vane tip angle of 60°, with a duct size of 2 × 2 square inches, are compared with the experimental data at several axial locations as well as with centerline data. Both mean and unsteady turbulent quantities obtained through the numerical simulations are validated with the experimental data (Cai et al., 2005). The methodology is extended to the confinements effect on mean flow characteristics. The time scale and length scale are useful parameters to get the desired results. The results show that with an increase in the confinement ratio, the recirculation length increases proportionally. A sample of three cases has been documented in this paper. The novelty of the paper is the modelling practices (grid/unsteady models) for a parametric study of LDI are established, and the mean confinement effects are validated with experimental data. The spectrum of turbulent energies is well captured by LES, and trends are aligned with experimental data. The methodology can be extended to reacting flows also to study the effect of swirl angle, fuel injection on aerodynamics, droplet characteristics and emissions.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-15
      DOI: 10.1108/AEAT-11-2021-0348
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Analyzing well-to-pump emissions of electric and conventional jet fuel for
           aircraft propulsion

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      Authors: Melih Yildiz , Utku Kale , Andras Nagy
      Abstract: The purpose of this study is to show the emissions related to electric consumption in electric aviation. Aviation, being one of the main transportation and economical driver of global trade and consumerism, is responsible for an important ratio of anthropogenic emissions. Electric energy use in aircraft propulsion is gaining interest as a method of providing sustainable and environmentally friendly aviation. However, the production of electricity is more energy and emission sensitive compared to conventional jet fuel. A well-to-pump (WTP) energy use and emission analysis were conducted to compare the electricity and conventional jet fuel emissions. For the calculations, a software and related database which is developed by Argonne’s Greenhouse gas, Regulated Emissions, and Energy use in Transportation (GREET®) model is used to determine WTP analysis for electricity production and delivery pathways and compared it to baseline conventional jet fuel. The WTP results show that electricity production and transmission have nine times higher average emissions compared to WTP emissions of conventional jet fuel. The future projection of emission calculations presented in this paper reveals that generating electricity from more renewable sources provides only a 50% reduction in general emissions. The electricity emission results are sensitive to the sources of production. The main focus of this study is to analyze the WTP emissions of electric energy and conventional jet fuel for use on hybrid aircraft propulsion.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-13
      DOI: 10.1108/AEAT-02-2021-0032
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Enabling SAT single pilot operations: tactical separation system design
           advancements in the COAST project

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      Authors: Vittorio Di Vito , Giulia Torrano , Giovanni Cerasuolo , Michele Ferrucci
      Abstract: This paper aims to describe the advancements of the activities that have been carried out, in the Cost-Optimized Avionics SysTem (COAST) project, to complete the design and in-flight demonstration of the Tactical Separation System (TSS), which is an automatic support system to the pilot’s decision-making, onboard on small air transport (SAT) vehicles under single pilot operations, in the separation management. In the framework of the Clean Sky 2 funded project COAST, some enabling technologies for single pilot operations in the EASA CS-23 category vehicles are designed and demonstrated in flight. Among the relevant flight management technologies addressed in the project, the specific one devoted to the real-time support to pilot’s decision-making in maintaining the vehicle self-separation is the TSS, designed by the Italian Aerospace Research Centre. The TSS design started in the year 2016 and has been completed in the year 2021 after successful in-flight demonstration in the dedicated flight test campaign. The system has been validated by means of several simulation campaigns and finally demonstrated its effectiveness in providing its intended functionalities (situational awareness, conflict detection, conflict resolution) to the pilot in real flight trials, involving the presence of real conflicting aircraft. The TSS contributes enabling the implementation of single pilot operations in CS-23 category vehicles, thanks to the possibility to support the pilot with provision of consolidated traffic picture, detection of conflicting surrounding traffic and suggestion of suitable conflict resolution manoeuvre real-time during the flight, through dedicated human–machine interface designed on purpose. The TSS supports the new separation modes that are envisaged in the future SESAR ATM target concept, with particular reference to the possible delegation of the separation responsibility to the pilot.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-12
      DOI: 10.1108/AEAT-02-2022-0042
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Experimental and numerical analysis of humpback whale inspired tubercles
           on swept wings

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      Authors: Jeena Joseph , Sathyabhama A. , Surya Sridhar
      Abstract: With aims to increase the aerodynamic efficiency of aerodynamic surfaces, study on flow control over these surfaces has gained importance. With the addition of flow control devices such as synthetic jets and vortex generators, the flow characteristics can be modified over the surface and, at the same time, enhance the performance of the body. One such flow control device is the tubercle. Inspired by the humpback whale’s flippers, these leading-edge serrations have improved the aerodynamic efficiency and the lift characteristics of airfoils and wings. This paper aims to discusses in detail the flow physics associated with tubercles and their effect on swept wings. This study involves a series of experimental and numerical analyses that have been performed on four different wing configurations, with four different sweep angles corresponding to 0°, 10°, 20° and 30° at a low Reynolds number corresponding to Rec=100,000. Results indicate that the effect of tubercles diminishes with an increase in wing sweep. A significant performance enhancement was observed in the stall and post-stall regions. The addition of tubercles led to a smooth post-stall lift characteristic compared to the sudden loss in the lift with regular wings. Among the four different wings under observation, it was found that tubercles were most effective on the 0° configuration (no sweep), showing a 10.8% increment in maximum lift and a 38.5% increase in the average lift generated in the post-stall region. Tubercles were least effective on 30° configuration. Furthermore, with an increase in wing sweep, co-rotating vortices were distinctly observed rather than counter-rotating vortices. While extensive numerical and experimental studies have been performed on straight wings with tubercles, studies on the tubercle effect on swept wings at low Reynolds number are minimal and mainly experimental in nature. This study uses numerical methods to explore the complex flow physics associated with tubercles and their implementation on swept wings. This study can be used as an introductory study to implement passive flow control devices in the low Reynolds number regime.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-12
      DOI: 10.1108/AEAT-04-2021-0114
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Numerical study of the yaw control of flapless aircraft

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      Authors: Ling-Xiao Li , He-Yong Xu , Zhi-Jie Fu , Zeng-Chun Huang
      Abstract: The purpose of this paper is to study the yaw control of the flapless aircraft and investigate the equivalent control effect (ECE) and the power consumption of the pneumatic control. The control effects of the mechanical control and the pneumatic control are calculated and the ECE curves are obtained. The power consumption of the pneumatic control is analyzed. A new pneumatic drag-type yaw control method is proposed. The mechanisms of the drag-type yaw control and the conventional thrust-type yaw control are explored. The drag-type yaw control is divided into two combined blowing forms: inner-top outer-bottom blowing and inner-bottom outer-top blowing. The differences between two kinds of the drag-type yaw control at a small angle of attack and a large angle of attack are explored. The ECE curves of the pneumatic control are obtained. The power consumption of the drag-type yaw control is much lower than that of the thrust type. The lift coefficient of the inner-top outer-bottom blowing is higher than that of the inner-bottom outer-top blowing, but the inner-bottom outer-top blowing has higher efficiency of the yaw control at a large angle of attack. This paper contributes to the research of the flapless aircraft. A new pneumatic drag-type yaw control method of the flapless aircraft is proposed.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-12
      DOI: 10.1108/AEAT-11-2021-0351
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Gas turbine system identification using a bilayer equilibrium manifold
           expansion model

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      Authors: Linhai Zhu , Liu Jinfu , Yujia Ma , Mingliang Bai , Weixing Zhou , Daren Yu
      Abstract: This paper aims to establish a multi-input equilibrium manifold expansion (EME) model for gas turbine (GT). It proposes that the extension of model input dimension is realized based on similarity theory and affine structure in the framework of single-input EME model. The study aims to expand the scope of application of the EME model so that it can be used for the control or fault diagnosis of GTs. In this paper, the concepts of corrected equilibrium manifold expansion (CEME) model and multi-cell equilibrium manifold expansion (MEME) model are first proposed. This paper uses theoretical analysis and simulation experiments to demonstrate the effectiveness of the bilayer equilibrium manifold expansion (BEME) model, which is a combination of the CEME and the MEME models. Simulation experiments include confirmatory experiments and comparative experiments. The paper provides a new sight into building a multiple-input EME (MI-EME) model for GTs. The proposed method can build an accurate and robust MI-EME model that has superior performance compared with widely used nonlinear models including Wiener model (WM), Hammerstein model (HM), Hammerstein–Wiener model (HWM) and nonlinear autoregressive with exogenous inputs (NARX) network model. In terms of accuracy, the maximum error percentage of the proposed model is just 1.309%, far less than WM, HM and HWM. In terms of the stability of model calculation, the range of the mean error percentage of the proposed model is just a quarter of that of NARX network model. The paper fulfills the construction of a novel multi-input nonlinear model, which has laid a foundation for the follow-up research of model-based GT fault detection and isolation or GT control.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-07
      DOI: 10.1108/AEAT-01-2020-0016
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Analysis of thermal stability and characterization of paraffin-blended
           hybrid fuels

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      Authors: Saravanan G. , Shanmugam S. , AR. Veerappan
      Abstract: The purpose of this study is to investigate the physical, chemical and thermal characteristics of paraffin-blended fuels to determine their suitability as fuel in hybrid rockets. Wax fuels are viable and efficient alternatives to conventional rocket fuels, having excellent structural strength and thermal and mechanical properties. The authors report a study of the morphological, chemical and thermal properties of paraffin wax with and without additives for use as fuels in hybrid rockets. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used for the morphological and chemical characterizations of the fuel blends. The thermal stability and combustion characteristics were assessed under an atmosphere of nitrogen by the simultaneous application of thermogravimetry and differential scanning calorimetry techniques. The melting temperatures for pure paraffin and other formulations were around 61°C as seen in differential scanning calorimetry experiments. Variations in the compositions of monoesters, n-alkanes, fatty acids, carboxylic acids methyl and hydroxyl esters in the fuel samples were assessed using Fourier transform infrared spectroscopy. The assessment criterion was chosen as the relative content of carbonyl groups, and the ratio of the stretching vibration of the C–C bonds to the deformation vibration of the aliphatic carbon–hydrogen bonds was taken as the basis for the quantitative calibration. The crystal phases identified by X-ray diffraction were used to identify nonlinear chemicals and alkane lengths. Scanning electron microscopy validated homogeneity in the paraffin-blended samples. This study presents the thermal stability and other relevant characteristics of fuel formulations comprising unconventional blends.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-07
      DOI: 10.1108/AEAT-11-2021-0323
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Safety performance functions to predict separation minima infringements in
           en-route airspace

         This is an Open Access Article Open Access Article

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      Authors: Raquel Delgado-Aguilera Jurado , Victor Fernando Gómez Comendador , María Zamarreño Suárez , Francisco Pérez Moreno , Christian Eduardo Verdonk Gallego , Rosa María Arnaldo Valdes
      Abstract: The purpose of this study is to establish a systematic framework to characterise the safety of air routes, in terms of separation minima infringements (SMIs) between en-route aircraft, based on the definition of models known as safety performance functions. Techniques with high predictive capability were selected that enable both expert knowledge and data to be harnessed: Bayesian networks. It was necessary to establish a conceptual framework that integrates the knowledge currently available on the causality and precursors of SMIs with the hindsight derived from the analysis of the type of data available. To translate the conceptual framework into a set of causal subnets, the concepts of air traffic management (ATM) barrier model and event trees have been incorporated. The model combines analytics and insights, as well as predictive capability, to answer the question of how airspace separation infringements are produced and what their frequency of occurrence will be. The main outputs of the network are the predicted probability of success for the ATM barriers and the predicted probability distribution of the vertical and horizontal separation of an aircraft in its closest point of approach. The main contribution of this work is that, by virtue of the calculation capacity obtained, the network can be used to draw conclusions about the impact that a modification of the airspace and of the traffic, or operational conditions, would have on the effectiveness of the barriers and on the final distributions of distance between aircraft in the CPA, thereby estimating the probability of SMI.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-07
      DOI: 10.1108/AEAT-11-2021-0331
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Estimation of lift characteristics of a subscale fighter using low-cost
           experimental methods

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      Authors: Leonardo Murilo Nepomuceno , Roberto Gil Annes da Silva , Alejandro Sobron , Petter Krus , David Lundström
      Abstract: While computational methods are prevalent in aircraft conceptual design, recent advances in mechatronics and manufacturing are lowering the cost of practical experiments. Focussing on a relatively simple property, the lift curve, this study aims to increase understanding of how basic aerodynamic characteristics of a complex stealth configuration can be estimated experimentally using low-cost equipment, rapid prototyping methods and remotely piloted aircraft. Lift curve estimates are obtained from a wind tunnel test of a three-dimensional-printed, 3.8%-scale model of a generic fighter and from flight testing a 14%-scale demonstrator using both a simple and a more advanced identification technique based on neural networks. These results are compared to a computational fluid dynamics study, a panel method and a straightforward, theoretical approach based on radical geometry simplifications. Besides a good agreement in the linear region, discrepancies at high angles of attack reveal the shortcomings of each method. The remotely piloted model manages to provide consistent results beyond the physical limitations of the wind tunnel although it seems limited by instrumentation capabilities and unmodelled thrust effects. Physical models can, even though low-cost experiments, expand the capabilities of other aerodynamic tools and contribute to reducing uncertainty when other estimations diverge. This study highlights the limitations of commonly used aerodynamic methods and shows how low-cost prototyping and testing can complement or validate other estimations in the early study of a complex configuration.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-06
      DOI: 10.1108/AEAT-04-2021-0105
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Physics informed neural networks for triple deck

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      Authors: Abderrahmane Belkallouche , Tahar Rezoug , Laurent Dala , Kian Tan
      Abstract: This paper aims to introduce physics-informed neural networks (PINN) applied to the two-dimensional steady-state laminar Navier–Stokes equations over a flat plate with roughness elements and specified local heating. The method bridges the gap between asymptotics theory and three-dimensional turbulent flow analyses, characterized by high costs in analysis setups and prohibitive computing times. The results indicate the possibility of using surface heating or wavy surface to control the incoming flow field. The understanding of the flow control mechanism is normally caused by the unsteady interactions between the aircraft structure and the turbulent flows as well as some studies have shown, surface roughness can significantly influence the fluid dynamics by inducing perturbations in the velocity profile. The description of the boundary-layer flow, based upon a triple-deck structure, shows how a wavy surface and a local surface heating generate an interaction between the inviscid region and the viscous region near the flat plate. To the best of the authors’ knowledge, the presented approach is especially original in relation to the innovative concept of PINN as a solver of the asymptotic triple-deck method applied to the viscous–inviscid boundary layer interaction.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-06
      DOI: 10.1108/AEAT-10-2021-0309
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Non-singular fixed-time pose tracking control for spacecraft with
           dead-zone input

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      Authors: Yuxia Ji , Li Chen , Jun Zhang , Dexin Zhang , Xiaowei Shao
      Abstract: The purpose of this paper is to investigate the pose control of rigid spacecraft subject to dead-zone input, unknown external disturbance and parametric uncertainty in space maneuvering mission. First, a 6-Degree of Freedom (DOF) dynamic model of rigid spacecraft with dead-zone input, unknown external disturbances and parametric uncertainty is derived. Second, a super-twisting-like fixed-time disturbance observer (FTDO) with strong robustness is developed to estimate the lumped disturbances in fixed time. Based on the proposed observer, a non-singular fixed-time terminal sliding-mode (NFTSM) controller with superior performance is proposed. Different from the existing sliding-mode controllers, the proposed control scheme can directly avoid the singularity in the controller design and speed up the convergence rate with improved control accuracy. Moreover, no prior knowledge of lumped disturbances’ upper bound and its first derivatives is required. The fixed-time stability of the entire closed-loop system is rigorously proved in the Lyapunov framework. Finally, the effectiveness and superiority of the proposed control scheme are proved by comparison with existing approaches. The proposed NFTSM controller can merely be applied to a specific type of spacecrafts, as the relevant system states should be measurable. A NFTSM controller based on a super-twisting-like FTDO can efficiently deal with dead-zone input, unknown external disturbance and parametric uncertainty for spacecraft pose control. This investigation uses NFTSM control and super-twisting-like FTDO to achieve spacecraft pose control subject to dead-zone input, unknown external disturbance and parametric uncertainty.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-04
      DOI: 10.1108/AEAT-08-2021-0243
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Drone-based delivery: a concurrent heuristic approach using a genetic
           algorithm

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      Authors: Khin Thida San , Yoon Seok Chang
      Abstract: The purpose of this study is to solve NP-Hard drone routing problem for the last-mile distribution. This is suitable for the multi-drones parcel delivery for the various items from a warehouse to many locations. This study conducts as a mission assignment of the single location per flight with the constraint satisfactions such as various payloads in weight, drone speeds, flight times and coverage distances. A genetic algorithm is modified as the concurrent heuristics approach (GCH), which has the knapsack problem dealing initialization, gene elitism (crossover) and gene replacement (mutation). Those proposed operators can reduce the execution time consuming and enhance the routing assignment of multiple drones. The evaluation value of the routing assignment can be calculated from the chromosome/individual representation by applying the proposed concurrent fitness. This study optimizes the total traveling time to accomplish the distribution. GCH is flexible and can provide a result according to the first-come-first-served, demanded weight or distance priority. GCH is an alternative option, which differs from conventional vehicle routing researches. Such researches (traveling time optimization) attempt to minimize the total traveling time, distance or the number of vehicles by assuming all vehicles have the same traveling speed; therefore, a specific vehicle assignment to a location is neglected. Moreover, the main drawback is those concepts can lead the repeated selection of best quality vehicles concerning the speed without considering the vehicle fleet size and coverage distance while this study defines the various speeds for the vehicles. Unlike those, the concurrent concept ensures a faster delivery accomplishment by sharing the work load with all participant vehicles concerning to their different capabilities. If the concurrent assignment is applied to the drone delivery effectively, the entire delivery can be accomplished relatively faster than the traveling time optimization.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-01
      DOI: 10.1108/AEAT-07-2020-0138
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Mechanical aspects of mothership with sensing drones system

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      Authors: Aleksandra Pakuła , Grzegorz Muchla , Bartosz Załęcki , Michał Jakub Modzelewski , Tomasz Goetzendorf-Grabowski
      Abstract: This paper aims to describe the mechanical aspects of unmanned Mothership Plane and Sensing Drones. The presented conceptual system shows the idea and possible way of designing different sizes and objective systems based on experience gained during the SAE Aero Design Competition. The UAS is based on a SAE Aero Design Competition designed and manufactured Mothership Plane converted to a high endurance platform modified to launch up to six small copters. The process of designing and converting the Mothership is described. The methodology of selecting and planning either the structure or hardware of the drones is presented. A key finding is that the presented conception of mothership plane deploying in flight a group of small sensing multirotors is achievable. Moreover, the modular build of the system provides the possibility to adapt currently existing unmanned aircrafts to be converted to the described mothership plane. To conduct flight tests and to study encountered problems. Presentation of the unmanned aerial system (UAS) concept that can be used to scan an area and create 3D maps for Search and Rescue missions as well as agriculture applications. The paper describes the conceptual approach to design a UAS consisting of the mothership plane and the sensing drones. The paper highlights the potential solutions gained by using such a UAS. The focus is to present a technology and system that can perform real time observations in widespread and difficult to reach areas.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-25
      DOI: 10.1108/AEAT-12-2020-0320
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Influencing factors of polarization coefficient of hollow fiber membrane

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      Authors: Ruihua Zhang , Weihua Liu
      Abstract: The purpose of this study is to improve the performance of hollow fiber membrane and improve the separation efficiency. By establishing a mathematical model of hollow fiber membrane gas separation, the influences of parameters such as pressure difference between the inside and outside of the filament, initial oxygen concentration of intake air, intake air flow rate and back pressure outside the filament on the polarization coefficient were analyzed, so as to explore the degree of influence of operating parameters on the concentration polarization, and put forward a technical scheme to reduce the concentration polarization. Factors such as pressure difference between the inside and outside of the filament, initial oxygen concentration of intake air, intake air flow rate and back pressure outside the filament have a certain effect on the polarization coefficient. Among them, the polarization coefficient is positively correlated with pressure difference inside and outside the filament, initial oxygen concentration of intake air and back pressure outside the filament, and is negatively correlated with intake air flow. Negative pressure suction on the permeation side can be used to increase the membrane permeation flow rate and reduce the concentration polarization. The influence of concentration polarization on membrane performance is reduced by controlling various factors.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-24
      DOI: 10.1108/AEAT-04-2021-0099
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Determining aircraft maintenance times in civil aviation under the
           learning effect

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      Authors: Uğur Atici , Mehmet Burak Şenol
      Abstract: Scheduling of aircraft maintenance operations is a gap in the literature. Maintenance times should be determined close to the real-life to schedule aircraft maintenance operations effectively. The learning effect, which has been studied extensively in the machine scheduling literature, has not been investigated on aircraft maintenance times. In the literature, the production times under the learning effect have been examined in numerous studies but for merely manufacturing and assembly lines. A model for determining base and line maintenance times in civil aviation under the learning effect has not been proposed yet. It is pretty challenging to determine aircraft maintenance times due to the various aircraft configurations, extended maintenance periods, different worker shifts and workers with diverse experience and education levels. The purpose of this study is to determine accurate aircraft maintenance times rigorously with a new model which includes the group learning effect with the multi-products and shifts, plateau effect, multi sub-operations and labour firings/rotations. Aircraft maintenance operations are carried out in shifts. Each maintenance operation consists of many sub-operations that are performed by groups of workers. Thus, various models, e.g. learning curve for maintenance line (MLC), MLC with plateau factor (MPLC), MLC with group factor (MGLC) were developed and used in this study. The performance and efficiency of the models were compared with the current models in the literature, such as the Yelle Learning model (Yelle), single learning curve (SLC) model and SLC with plateau factor model (SLC-P). Estimations of all these models were compared with actual aircraft maintenance times in terms of mean absolute deviation (MAD), mean absolute percentage error (MAPE) and mean square of the error (MSE) values. Seven years (2014–2020) maintenance data of one of the top ten maintenance companies in civil aviation were analysed for the application and comparison of learning curve models. The best estimations in terms of MAD, MAPE and MSE values are, respectively, gathered by MGLC, SLC-P, MPLC, MLC, SLC and YELLE models. This study revealed that the models (MGLC, SLC-P, MPLC), including the plateau factor, are more efficient in estimating accurate aircraft maintenance times. Furthermore, MGLC always made the closest estimations to the actual aircraft maintenance times. The results show that the MGLC model is more accurate than all of the other models for all sub-operations. The MGLC model is promising for the aviation industry in determining aircraft maintenance times under the learning effect. In this study, learning curve models, considering groups of workers working in shifts, have been developed and employed for the first time for estimating more realistic maintenance times in aircraft maintenance. To the best of the authors’ knowledge, the effect of group learning on maintenance times in aircraft maintenance operations has not been studied. The novelty of the models are their applicability for groups of workers with different education and experience levels working in the same shift where they can learn in accordance with their proportion of contribution to the work and learning continues throughout shifts. The validity of the proposed models has been proved by comparing actual aircraft maintenance data. In practice, the MGLC model could efficiently be used for aircraft maintenance planning, certifying staff performance evaluations and maintenance trainings. Moreover, aircraft maintenance activities can be scheduled under the learning effect and a more realistic maintenance plan could be gathered in that way.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-24
      DOI: 10.1108/AEAT-05-2021-0153
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Initial airworthiness requirements for aircraft electric propulsion

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      Authors: Melih Yildiz
      Abstract: The purpose of this paper is to analyze the electric propulsion use in civil aviation and propose a framework for certification of electric propulsion subsystems. Although electric propulsion architectures are discussed as key technology for the future of aviation, the industry standards as well as regulations fail to cover the application in full extent, specifically for commercial large airplanes. This paper proposes an approach for the analyses of reliability and certification of the new-generation propulsion system by pointing out the “common structure” among the possible architectures. The research process used in this paper consists of following steps: the challenges of the hybrid-electric propulsion is listed, the architectures of the hybrid-electric applications in the literature are identified, the differences of the hybrid architectures from the present applications by means of application and standardization are discovered, the architectures are analyzed and the two main subsystems are defined – the present combustion system and the common unit, which is a similar structure used in all-electric aircraft. For this purpose, the standards used for design basis and certification of the present propulsion system and their relationship with the subsystems of the architectures have been analyzed. The procedure for the reliability assessment of the system is given, a framework for the safety assessment and the certification of the propulsion systems is proposed to make it easier and without sacrificing the already accumulated experience. This study shows that by using the common unit, the present certification framework can be used, by focusing on the reliability of the common unit and its integration with the rest of the architecture. A specific definition of common unit is proposed, to point out the difference in certification efforts of hybrid-electric propulsion architectures. Yet, there is no data available for propulsion-level airborne battery and electrical systems to assess the reliability. Thus, dividing the propulsion system into two main systems and providing a model for certification of the common unit sub-system would be beneficial for easy deployment of the hybrid architectures both for design and for certification. In this paper, it is proposed that by using this common unit, the present certification framework can be used as it is, by focusing on the reliability of the common unit and its integration with the rest of the architecture. The aircraft certification regulations act in two ways: they provide a starting point for new design projects, and they are a basis for certification of the final system. This study aims to draw focus on certification issues on the new-generation hybrid-electric propulsion systems. With the introduction of hybrid-electric propulsion for large aircraft, the present standards (CS-25, CS-E, CS-P, CS-Battery and CS-APU) create an obstacle for further progress as their borders get into each other. Instead of developing a new set of standard(s), this paper proposes a new approach by dividing the propulsion system into two subsystems. This research proposes a definition of “common unit” for simplification of the hybrid-electric propulsion architectures for large civil aircraft. The common unit consists of both battery and electrical components and their reliability shall be considered for hybrid-electric propulsion.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-24
      DOI: 10.1108/AEAT-08-2021-0238
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • ACAS installation on unmanned aerial vehicles: effectiveness and safety
           issues

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      Authors: Lidija Tomić , Olja Čokorilo , Ljubiša Vasov , Branimir Stojiljković
      Abstract: The paper aims to investigate the compatibility of manned-aircraft airborne collision avoidance systems (ACAS) for use on unmanned aerial vehicles (UAV). The paper uses the Fault Tree method for defining ACAS model adapted for the UAV operations, with the aim of showing the presence of certain factors that configure in such ACAS system, and whose failure can lead to an adverse event – mid-air collision. Based on the effectiveness analysis of ACAS solution adapted for the UAV operations, for given inputs, it can be concluded that the probability of ACAS failure is on the order of 10–4, as well as that in the case of autonomous ACAS solution for the UAV, the probability is reduced to 10–5. The most influential factors for the failure of the UAV’s ACAS are as follows: technical implications on the UAV, human factor, sensor error, communication and C2 link issue. The established model could be used both in the UAV’s ACAS design and application phases, with the aim of assessing the effectiveness of the adopted solution. The model outputs not only highlight the critical points of the system but also provide the basis for defining the Target Level of Safety (TLOS) for the UAV operations. The developed model can be expected to speed up the design and adoption process of ACAS solutions for the UAVs. Also, the paper presents one of the first attempts to quantify TLOS for the UAV operations in the context of collision avoidance systems.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-24
      DOI: 10.1108/AEAT-10-2021-0313
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • The effect of environmental pressure changes on the bond strength between
           zirconia ceramic and adhesive resin cement

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      Authors: Secil Ozkan Ata , Canan Akay , Nazim Ata
      Abstract: The purpose of this study was to investigate the effect of the environmental pressure changes on the bond strength between zirconia ceramics and adhesive resin cement. In total, 40 rectangular-shaped zirconium-oxide ceramic specimens were prepared. For surface modification, all zirconia specimens were sandblasted with 50 μm alumina particles. The composite resin discs were bonded to modified zirconia surfaces with resin cement. The specimens were divided into four groups; hyperbaric, hypobaric, hyperbaric + hypobaric and control group. The specimen underwent pressure cycles for 30 days. The shear bond strength test was performed by using the universal testing machine, and failures of the debonded samples were examined with scanning electron microscopy and light microscope. No significant difference in bond strength was found between the hyperbaric, hypobaric and control groups after 30 days (p > 0.05). However, there was a significant difference in the hyperbaric + hypobaric group compared to the control group (p = 0.022). Also, the Weibull modulus was highest in control group and lowest in the hyperbaric + hypobaric group. Barometric changes due to flying followed by diving may have an adverse effect on the retention of zirconia ceramics. Care should be taken in the selection of materials for dental treatment of people who are exposed to environmental pressure changes.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-24
      DOI: 10.1108/AEAT-11-2021-0336
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • How much workload is workload' A human neurophysiological and
           affective-cognitive performance measurement methodology for ATCOs

         This is an Open Access Article Open Access Article

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      Authors: María Zamarreño Suárez , Rosa María Arnaldo Valdés , Francisco Pérez Moreno , Raquel Delgado-Aguilera Jurado , Patricia María López de Frutos , Víctor Fernando Gómez Comendador
      Abstract: Air traffic controllers (ATCOs) play a fundamental role in the safe, orderly and efficient management of air traffic. In the interests of improving safety, it would be beneficial to know what the workload thresholds are that permit ATCOs to carry out their functions safely and efficiently. The purpose of this paper is to present the development of a simulation platform to be able to validate an affective-cognitive performance methodology based on neurophysiological factors applied to ATCOs, to define the said thresholds. The process followed in setting up the simulation platform is explained, with particular emphasis on the design of the program of exercises. The tools designed to obtain additional information on the actions of ATCOs and how their workload will be evaluated are also explained. To establish the desired methodology, a series of exercises has been designed to be simulated. This paper describes the project development framework and validates it, taking preliminary results as a reference. The validation of the framework justifies further study to extend the preliminary results. This paper describes the first part of the project only, i.e. the definition of the problem and a proposed methodology to arrive at a workable solution. Further work will concentrate on carrying out a program of simulations and subsequent detailed analysis of the data obtained, based on the conclusions drawn from the preliminary results presented. The methodology will be an important tool from the point of view of safety and the work carried out by ATCOs. This first phase is crucial as it provides a solid foundation for later stages.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-23
      DOI: 10.1108/AEAT-11-2021-0328
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Structural efficiency of block for aviation piston heavy fuel engine

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      Authors: Zhongjian Pan , Qinghua He , Jing Yang
      Abstract: High reliability and high power-to-weight ratio are the technical difficulties in the development of aviation piston heavy fuel engines. This paper aims to provide a design evaluation method of the aero piston engine block, which can help R&D personnel quickly evaluate the performance of engine block, including effective bearing capacity and fatigue deformation, save a lot of experimental time and shorten the R&D cycle. In this paper, structural efficiency is used to evaluate the reliability and durability of the engine block. Structural efficiency is a new evaluation method that lists its corresponding connotation according to different objects. In this paper, the function of the engine block in the engine is explained in detail, and three quantifiable connotations of the structural efficiency of the engine block are put forward. In the subsequent calculation, the calculation is carried out according to the three indexes, and the calculation results are used as the indexes to evaluate the performance of the engine block. The structural efficiency evaluation method proposed in this paper can quickly and effectively evaluate the performance of the block from many aspects. Under the same boundary conditions, the two design schemes are simulated and analyzed, and the durability test is carried out. The analysis and experimental results show that Scheme 2 has good performance, which verifies the feasibility of the evaluation method. This paper provides a method for rapid evaluation of engine block performance.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-21
      DOI: 10.1108/AEAT-08-2021-0244
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Fractional order sliding mode control based on delayed output observer for
           unmanned aircraft system

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      Authors: Ashutosh Bist , Swati Sondhi
      Abstract: This paper aims to design the fractional order sliding mode controller for highly maneuverable remote piloted unmanned aircraft with time-varying delays. With the assumption that the time-varying delays are bounded and identical for different outputs, an observer-based control technique is implied which reformulates the state variables based on the system model and delayed outputs. The estimated state variables are fed as feedback into the controller. Based on the delayed output observer, a fractional order sliding mode controller is designed. Further, the stability of the closed-loop system is analyzed and asymptotical convergence is realized using Lyapunov–Razumikhin theorem. The simulation is done in Matlab and Simulink. The parametric variations and trajectory tracking results are illustrated which looks propitious. In practical operation, measurement signal is often delayed, which significantly degrade the control performance or even disturb the stability. It is emphasized to choose attitude as the evaluation indicator for unmanned aerial vehicle time delay. A novel fractional order sliding mode control technique is designed to enhance the trajectory tracking, thus autonomous flight performance, of the aircraft system. Also, the main idea behind this novel procedure is formulated for minimizing the parametric variations in presence of time delays.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-21
      DOI: 10.1108/AEAT-11-2020-0245
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Investigation of wind effect on different quadrotors

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      Authors: Hamdi Ercan , Hamdi Ulucan , Muharrem Selim Can
      Abstract: Although windy weather conditions have a significant effect on the flight safety and stability of any aircraft, the fact that quadrotors are lighter than other aircraft makes them more sensitive to the wind. This study aims to examine the extent to which quadrotors and their sensors, which are used in many fields and whose use is expected to increase significantly in the future, are affected by wind. Flight experiments were carried out on different routes assigned by using Pixhawk Holybro 4 and Radiolink flight controllers. In these flight experiments, quadrotors were exposed to winds at different speeds and directions. In the flight experiments, the deviation amounts in the quadrotor’s route at which wind speed was determined, and it was seen that these deviations were very serious and affected the safe flight at high wind speeds. According to the sensor information obtained from both different quadrotors’ flight experiments at different wind speeds, it was determined that the wind decreased the sensors’ accuracy. It is foreseen that the data obtained in this study will be a source to be used in the design of quadrotors to be used in public areas in the future and to take the wind into account for safe flight. In this study, numerous flight tests were carried out experimentally at various speeds from low speeds to high speeds on different routes using different flight controllers. The deviation data on the obtained routes and the effect of the wind on the sensors are experienced in real atmospheric conditions.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-18
      DOI: 10.1108/AEAT-09-2021-0288
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Vibration response analysis and hoop layout optimization of spatial
           pipeline under random excitation

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      Authors: Donghai Wang , Wei Sun , Zhihui Gao , Hui Li
      Abstract: In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline system effectively by adjusting the hoop layout. In this paper, a spatial pipeline supported by multi-hoops is taken as the object, the methods of solution of the vibration response of the pipeline system by using pseudo excitation and hoop layouts optimization with amplitude reduction of vibration response as the goal are presented. First, the finite element model of the spatial pipeline system is presented. Then, an optimization model spatial pipeline is established. Finally, a case study is carried out to prove the rationality of the random vibration response analysis of the pipeline system. Furthermore, the proposed optimization model and genetic algorithm are applied to optimize the hoop layout. The results show that the maximum response variance after optimization is reduced by 32.8%, which proves the rationality of the developed hoop layout optimization method. The pseudo excitation method is used to solve the vibration response of aero-engine pipeline system, and the optimization of the hoop layout for aero-engine spatial pipelines under random excitation to reduce random vibration response is studied systematically.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-18
      DOI: 10.1108/AEAT-09-2021-0291
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Horizontal take-off of an insect-like FMAV based on stroke plane
           modulation

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      Authors: Zihao Chen , Weiping Zhang , Jiawang Mou , Kexin Zheng
      Abstract: Vertical take-off is commonly adopted in most insect-mimicking flapping-wing micro air vehicles (FMAV) while insects also adopt horizontal take-off from the ground. The purpose of this paper is to study how insects adjust their attitude in such a short time during horizontal take-off by means of designing and testing an FMAV based on stroke plane modulation. An FMAV prototype based on stroke plane rotating modulation is built to test the flight performance during horizontal take-off. Dynamic gain and decoupling mixer is added to compensate for the nonlinearity during the rotation angle of the stroke plane getting too large at the beginning of take-off. Force/torque test based on a six-axis sensor validates the change of aerodynamic force and torque at different rotation angles. High-speed camera and motion capture system test the flight performance of horizontal take-off. Stroke plane modulation can provide a great initial pitch toque for FMAV to realize horizontal take-off. But the large range of rotation angles causes nonlinearity and coupling of roll and yaw. A dynamic gain and a mixer are added in the controller, and the FMAV successfully achieves horizontally taking off in less than 1 s. The research in this paper shows stroke plane modulation is suitable for insect’s horizontal take-off
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-18
      DOI: 10.1108/AEAT-11-2021-0338
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • The pre-process DV-UKF algorithm for high-precision attitude measurement
           with low-cost inertial sensor

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      Authors: Rong Wang , Jin Wu , Chong Li , Shengbo Qi , Xiangrui Meng , Xinning Wang , Chengxi Zhang
      Abstract: The purpose of this paper is to propose a high-precision attitude solution to solve the attitude drift problem caused by the dispersion of low-cost micro-electro-mechanical system devices in strap-down inertial navigation attitude solution of micro-quadrotor. In this study, a three-stage attitude estimation scheme that combines data preprocessing, gyro drifts prediction and enhanced unscented Kalman filtering (UKF) is proposed. By introducing a preprocessing model, the quaternion orientation is calculated as the composition of two algebraic quaternions, and the decoupling feature of the two quaternions makes the roll and pitch components independent of magnetic interference. A novel real-time based on differential value (DV) estimation algorithm is proposed for gyro drift. This novel solution prevents the impact of quartic characteristics and uses the iterative method to meet the requirement of real-time applications. A novel attitude determination algorithm, the pre-process DV-UKF algorithm, is proposed in combination with UKF based on the above solution and its characteristics. Compared to UKF, both simulation and experimental results demonstrate that the pre-process DV-UKF algorithm has higher reliability in attitude determination. The dynamic errors in the three directions of the attitude are below 2.0°, the static errors are all less than 0.2° and the absolute attitude errors tailored by average are about 47.98% compared to the UKF. This paper fulfils an identified need to achieve high-precision attitude estimation when using low-cost inertial devices in micro-quadrotor. The accuracy of the pre-process DV-UKF algorithm is superior to other products in the market.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-16
      DOI: 10.1108/AEAT-05-2021-0169
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Simultaneous autonomous system and powerplant design for morphing
           quadrotors

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      Authors: Hüseyin Şahin , Oguz Kose , Tugrul Oktay
      Abstract: This study aims to optimize autonomous performance (i.e. both longitudinal and lateral) and endurance of the quadrotor type aerial vehicle simultaneously depending on the autopilot gain coefficients and battery weight. Quadrotor design processes are critical to performance. Unmanned aerial vehicle durability is an important performance parameter. One of the factors affecting durability is the battery. Battery weight, energy capacity and discharge rate are important design parameters of the battery. In this study, proper autopilot gain coefficients and battery weight are obtained by using a stochastic optimization method named as simultaneous perturbation stochastic approximation (SPSA). Because there is no direct correlation between battery weight and battery energy density, artificial neural network (ANN) is benefited to obtain battery energy density corresponding to resulted battery weight found from SPSA algorithm. By using the SPSA algorithm optimum performance index is obtained, then obtained data is used for longitudinal and lateral autonomous flight simulations. With SPSA, the best proportional integrator and derivative (PID) coefficients and battery weight, energy efficiency and endurance were obtained in case of morphing. It takes a long time to find the most suitable battery values depending on quadrotor endurance. However, this situation can be overcome with the proposed SPSA. It is very useful to determine quadrotor endurance, PID coefficients and morphing rate using the optimization method. Determining quadrotor endurance, PID coefficients and morphing rate using the optimization method provides advantages in terms of time, cost and practicality. The proposed method improves quadrotor endurance. In addition, with the SPSA optimization method and ANN, the parameters required for endurance will be obtained faster and more securely. In addition, the energy density according to the battery weight also contributes to the clean environment and energy efficiency.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-16
      DOI: 10.1108/AEAT-06-2021-0180
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • A holistic assessment of a stiffened panel production using a novel
           thermoplastic material and implementing the induction welding process

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      Authors: Christos Katsiropoulos , Spyros Pantelakis , Francesca Felline , Giuseppe Buccoliero , Silvio Pappada
      Abstract: The purpose of this paper is to investigate the feasibility to produce a novel aircraft full stiffened panel using entirely a new hybrid thermoplastic composite material allowing for appreciably lower processing temperatures as compared to conventional structural thermoplastic composites. For stiffening the fuselage skin panel, the out of autoclave welding of four composite stringers was obtained using a modified induction welding (IW) process. The quality of the welds was investigated using micro-tomography and the mechanical strength of the lap joints was assessed by means of single-lap shear strength (SLSS) tests. Moreover, a holistic design index was implemented as a decision support tool for selecting the optimal set of IW process parameters. Based on the index used, the quality as well as the entire life cycle cost and environmental impact are accounted for. Low porosity values as well as no deconsolidation were observed at the investigated application, and the average measured SLSS, even found lower, lies within the range of the respective values encountered in other similar high-performance applications. It is exhibited that after the optimization, the IW process offers significant potential to replace the autoclave process in welding applications. Thus, it paves the way for reduced cost and increased sustainability, while still meeting the predefined quality constraints. Although several studies on the IW application have been conducted, limited results exist by using novel thermoplastic materials for aircraft structural applications.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-15
      DOI: 10.1108/AEAT-12-2021-0362
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Numerical study of unmanned aerial vehicle (UAV) in dry microburst
           environment using large eddy simulation (LES) model

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      Authors: Somashekar V. , Immanuel Selwynraj A.
      Abstract: In a microburst wind, the profiles and characteristics are significantly different from those of normal boundary layer winds. The objective of this work is to study the microburst effect on the performance of aircraft for providing guidelines to frame escape strategies. Large eddy simulation model is used to study the effect of microburst by simulating the actual physical process of microburst-generated downdraft environment over the unmanned aerial vehicle. In this work, an attempt has been made to simulate the dry microburst (microburst not accompanied by rain) numerically using the impinging jet model to explore the effect of microburst at 12° angle of attack for flight take-off condition with a Mach number 0.04. The numerical results revealed the aerodynamic performance loss of an aircraft in the microburst-generated downdraft during take-off condition quantitatively. This could be a more valuable information to the aviation industry. The authors believe that the results shown in this paper will be useful for the designers of aircraft. This will also help train the pilots to control the airplanes in a microburst environment. Severe thunderstorms are significant weather phenomena that have a significant impact on various facets of national activity, including civil and defence operations, specifically aviation, space vehicle launch and agriculture, in addition to their potential to cause damage to life and property. The maximum percentage of pressure increases on the upper surface of the aircraft between 2 and 7 s is 99.86% under the microburst-generated downdraft condition. The flight escape maneuver could be initiated, before increasing the pressure on the upper surface of the aircraft. The aircraft flies with high airspeed through the microburst environment, where the microburst-generated downdraft is most severe.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-11
      DOI: 10.1108/AEAT-10-2021-0308
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Improved particle filter-based estimation of a quadrotor subjected to
           uncertainties

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      Authors: Aziz Kaba , Ahmet Ermeydan
      Abstract: The purpose of this paper is to present an improved particle filter-based attitude estimator for a quadrotor unmanned aerial vehicle (UAV) that addresses the degeneracy issues. Control of a quadrotor is not sufficient enough without an estimator to eliminate the noise from low-cost sensors. In this work, particle filter-based attitude estimator is proposed and used for nonlinear quadrotor dynamics. But, since recursive Bayesian estimation steps may rise degeneracy issues, the proposed scheme is improved with four different and widely used resampling algorithms. Robustness of the proposed schemes is tested under various scenarios that include different levels of uncertainty and different particle sizes. Statistical analyses are conducted to assess the error performance of the schemes. According to the statistical analysis, the proposed estimators are capable of reducing sensor noise up to 5x, increasing signal to noise ratio up to 2.5x and reducing the uncertainty bounds up to 36x with root mean square value of as low as 0.0024, mean absolute error value of 0.036, respectively. To the best of the authors’ knowledge, the originality of this paper is to propose a robust particle filter-based attitude estimator to eliminate the low-cost sensor errors of quadrotor UAVs.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-10
      DOI: 10.1108/AEAT-08-2021-0234
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Modeling of environmental effect factor and exergetic sustainability index
           with cuckoo search algorithm for a business jet

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      Authors: Ridvan Oruc , Tolga Baklacioglu , Onder Turan , Hakan Aydin
      Abstract: The purpose of this paper is to create models that predict exergetic sustainability index (ESI) and environmental effect factor (EEF) values with high accuracy according to various engine parameters. In this study, models were created to estimate ESI and EEF sustainability parameters in various flight phases for a business jet with a turboprop engine using the cuckoo search algorithm (CSA) method. The database used for modeling includes the various engine parameters (torque, engine airflow, gas generator speed, fuel mass flow, power and air-fuel ratio) obtained by running a business aircraft engine more than once at different settings and the actual ESI and EEF values obtained depending on these parameters. In addition, sensitivity analysis was performed to measure the effect of engine parameters on the models. Finally, the effect of the CSA number of nest (n) parameter on the model accuracy was investigated. It has been observed that the models predict ESI and EEF values with high accuracy. As a result of the sensitivity analysis, it was seen that the air-fuel ratio had a greater effect on the output parameters. These models are thought to assist in the exergetic environment analysis used to find the greatest losses for turboprop business jets and identify their causes and further improve system performance. Thus, they will be a useful tool to minimize the negative impact of business jet on environmental sustainability. To the best of the authors’ knowledge, this study stands out in the literature because it is the first exergo-metaheuristic approach developed with CSA for business aircraft engine; moreover, the data set used consists of real values.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-08
      DOI: 10.1108/AEAT-08-2021-0251
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Adaptive block backstepping control for a UAV performing lateral maneuvers
           under lateral c.g. uncertainty

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      Authors: Anukaran Khanna , Neelaksh Singh , Bijoy K. Mukherjee
      Abstract: Unmanned aerial vehicles (UAVs) have wide applications in surveillance and reconnaissance without risking human life. Due to unbalanced payload distribution or in-flight deployment, UAVs may undergo lateral center of gravity (c.g.) variations resulting in an asymmetric dynamic having significant longitudinal and lateral/directional coupling and hence more pronounced nonlinearity. Therefore, automatic control of UAVs becomes extremely difficult when it is forced to perform maneuvers under such imbalance in lateral mass distribution. The purpose of this paper is to design adaptive nonlinear control so that the UAV can perform some useful lateral/directional maneuver under lateral c.g. uncertainty. First the nominal lateral/directional dynamics of a fixed-wing UAV is framed into strict feedback form and then the block backstepping approach is used to design the controller to execute horizontal turn and aileron roll maneuvers under no lateral c.g. variation. Thereafter, an adaptive block backstepping controller is designed to adapt to uncertainty in lateral c.g. position considering an approximate model of the asymmetric dynamics. The proposed adaptive scheme is validated against the same two maneuvers as considered for the nominal case. First it is shown that the lateral/directional dynamics of a UAV can be converted to a block strict feedback form for executing some lateral/directional maneuvers. However, it was observed that the maneuver performance suffers significant performance degradation under lateral c.g. variations. To mitigate this issue, a simple and computationally inexpensive adaptive block backstepping scheme is proposed and validated. The adaptation law is further proved to be able to asymptotically estimate the actual c.g. location of the UAV. The proposed control scheme allows the UAV to automatically adapt to lateral c.g. variations so that the intended maneuvers are performed without any noticeable loss in maneuver performance. There are very few works available in the literature that address nonlinear control designs for executing specific lateral/directional maneuvers and, moreover, they consider symmetric UAVs or aircraft only. This paper addresses the practical problem of autonomous maneuvering for UAVs with unbalanced lateral mass distribution leading to shift of c.g. out of its plane of symmetry.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-07
      DOI: 10.1108/AEAT-08-2021-0231
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Experimental analysis of friction stir welded aviation grade AA8090 joints
           using Taguchi orthogonal array

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      Authors: Raghuraj Panwar , Pankaj Chandna
      Abstract: This paper aims to predict the performance of friction stir welded AA8090 joint. In the present study, Al-Li AA8090 plates are butt joined using friction stir welding (FSW). The experiments are designed and optimized using a Taguchi-orthogonal array. The experiments are conducted at three different process parameters, i.e. tool rotational speed (TRS), tool transverse speed (TTS) and dwell time (DT). The ultimate tensile strength (UTS) and microhardness (MH) are considered as response parameters. In addition, a statistical tool (ANOVA) is used to check the adequacy of experiment results. The maximum UTS of 220 MPa is obtained at a TRS of 1,400 rpm, tool TTS of 40 mm/min and DT of 15 s. The maximum microhardness is obtained for 1,400 rpm, 25 mm/min and 8 s, i.e. 108.6 HV. The microstructural showed that the minimum grain is observed at the nugget zone. Fractography analysis revealed the ductile behaviour of fractured surfaces. From the reported literature, it has been observed that very limited work is reported on the FSW of AA8090 alloy. Further, the thermal behaviour of welded joint is also observed in this experimental work.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-07
      DOI: 10.1108/AEAT-09-2021-0290
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • A case study on the effect of meteorological events on the efficiency of
           flight training organization

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      Authors: Ali Tatli , Erdogan Bocu , Tansu Filik , Tahir Hikmet Karakoc
      Abstract: The purpose of this study is to determine the meteorological events that affect flight training to make the training flight more efficient in a flight training organization (FTO) and to examine the effects of these events on FTO. Within the scope of this study, the flight training given at Eskisehir Technical University Pilotage Department (ESTU-P) is discussed, and the effect of meteorological events on flight training in this FTO is evaluated. When the two-year (2019–2020) flight training process of ESTU-P is examined, 45% of the flights planned for 2019, 25% of the flights planned for 2020 and 33% of the total flights in the two-year period could not be realized due to meteorological events. It is determined that this result naturally affects the efficiency of the FTO negatively. Meteorological events such as high temperature, fog and snow are among the main meteorological events that cause flight training to be interrupted. This study will create a framework for FTOs that have been or will be established.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-07
      DOI: 10.1108/AEAT-10-2021-0295
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • 6DOF nonlinear control loading system for a large transport aircraft
           simulator

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      Authors: Saeb Amir Ahmadi Chomachar , Ashok Kuppusamy
      Abstract: Flight simulators are one of the noticeable breakthroughs in aerospace engineering. One of the main compartments of flight simulators is its control loading system (CLS). The CLS functions as a generator of virtual aerodynamic control-loads over control columns of a simulator. This paper aims to present the design of a high-fidelity six six degrees of freedom (6DOF) nonlinear CLS for the Boeing-747 aircraft simulator. An introduction to CLS for flight motion simulators are first recapitulated. Afterward, the commanding devices are explained through schematics available in an engineering sense. This paper then presents in detail, the active control loading strategy and hardware design for the CLS, while also introducing the aerodynamic model structure. The satisfactory computer numerical simulations are presented before the paper ends up in concluding remarks. The multiple input multiple output (MIMO) 6DOF nonlinear CLS for Boeing-747 flight simulator has been successfully developed. The outcome of computer simulations in real-time verifies practicality of the design strategy. The research presented in this paper could be a simple roadmap for prototyping high-fidelity 6DOF nonlinear CLS for flight motion simulators. The available control architecture and hardware technologies cannot enable a high-fidelity load realization in a CLS. The existing research has not yet presented a 6DOF nonlinear MIMO CLS architecture along with the underlying controller setup for a high-fidelity load realization. In this paper, the design of a high-fidelity 6DOF nonlinear MIMO CLS for flight simulator of a large transport aircraft has been accomplished.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-04
      DOI: 10.1108/AEAT-08-2021-0240
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Closed-loop identification for aircraft flutter model parameters

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      Authors: Wang Jianhong
      Abstract: The purpose of this paper is to extend the authors’ previous contributions on aircraft flutter model parameters identification. Because closed-loop condition is more widely used in today’s practice, a closed-loop stochastic model of the aircraft flutter test is constructed to model the aircraft flutter process, whose input–output signals are all corrupted by the observed noises. Through using a rational transfer function, the equivalent property between the aircraft flutter model parameters and polynomial coefficients is established, and then the problem of aircraft flutter model parameters identification is turned to one closed-loop identification problem. An iterative identification algorithm is proposed to identify the unknown polynomial coefficients, being benefit for the latter flutter model parameter identification. Furthermore, as the closed-loop output corresponds to the flutter amplitude, so from the point of the minimization with respect to the variance of the closed-loop output, the optimal input signal and optimal feedback controller are all derived to achieve the zero flutter, respectively, for example, the optimal input spectrum and the detailed form for optimal feedback controller. First, model parameter identification for aircraft flutter is reviewed as one problem of parameter identification and this aircraft flutter model corresponds to one closed-loop stochastic model, whose input signal and output are corrupted by external noises. Second, for aircraft flutter closed-loop statistical model with statistical noise, an iterative identification algorithm is proposed to identify the unknown model parameters. Third, from the point of minimizing with respect to the variance of the closed-loop output, the optimal input signal and optimal feedback controller are all derived to achieve the zero flutter, respectively, for example, the optimal input spectrum and the detailed form for optimal feedback controller. This aircraft flutter model corresponds to one closed-loop stochastic model, whose input signal and output are corrupted by external noises. Then, identification algorithm and optimal input signal design are studied for aircraft flutter model parameter identification with statistical noise, respectively. It means the optimal input signal and optimal feedback controller are useful for the aircraft flutter model parameter identification within the constructed new closed-loop stochastic model. To the best of the authors’ knowledge, this problem of the model parameter identification for aircraft flutter is proposed by their previous work, and they proposed many identification strategies to identify these model parameters. This paper proposes a new closed-loop stochastic model to construct the aircraft flutter test, and some related topics are considered about this closed-loop identification for aircraft flutter model parameter identification in the framework of closed-loop condition.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-04
      DOI: 10.1108/AEAT-08-2021-0254
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Effect of stator height change on bearing life in aircraft autopilot
           servos

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      Authors: Gurkan Ortamevzi , Yalcin Sahin
      Abstract: The purpose of this paper is to make a more precise prediction of the life of servo motors used in aircraft. The variation of the axial load created by the wave washer for bearing, which is one of the factors affecting the bearing life of the electric motors and servo motors used in aircraft, was analyzed. In electric motors and servo motors that body as stator, the height of the stator stack affects the compression amount of the wave washer spring. Working with electric motor and servo manufacturers, production-related variations in stator height were determined by making multiple measurements. The reaction forces resulting from these compression amounts were simulated by mathematical modeling with the finite element method, and also experimentally measured on real parts. Results obtained with finite element method and real experiments were compared. By adding the force differences to the general operating conditions, the effect on the bearing life was theoretically determined. In a servo motor with this type of construction, the difference in stator height created different axial loads on the motor shaft. The difference of these loads affected the motor bearing life. The results implicated in terms of flight safety, maintenance operation and resource efficiency. The results of this study are effective in determining the maintenance intervals more clearly. This study can be used for the design criteria of aircraft servo motors. These servos, which are especially used to move the flight control surfaces, contribute to flight safety as the life expectancy will be clearer. This study may be effective in preventing aviation accidents caused by servo motors. It can make maintenance management more efficient. This study investigated the effect of aircraft servo motor design inputs on servo motor life, considering the production.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-04
      DOI: 10.1108/AEAT-08-2021-0257
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Combined effects of inlet airflow temperature and upper expansion angle on
           the performance of scramjet nozzle

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      Authors: Yifang Sun , Chunxu Duan , Renfu Li , Chenghu Li
      Abstract: The purpose of this paper is to study the combined effects of inlet airflow temperature and the expansion angle of the upper expansion surface (upper expansion angle) on the performance of the scramjet nozzle. The Spalart-Allmaras turbulence two-dimensional model of the nozzle is established for the study. The influence of inlet airflow temperature on the performance of the nozzle is analyzed by detecting the change of the wall pressure of the nozzle. The three angles are chosen for the upper expansion angle (βb) in the model: 8°, 12° and 16°. The temperature of inlet airflow is 600–1,800 K. The study results show that when the βb is 8° and 16°, the wall pressure of the nozzle has a complicated and large fluctuation with the inlet airflow temperature, while the wall pressure has little change as βb is 12°; the thrust coefficient, pitching moment coefficient and lift coefficient of the nozzle fluctuate greatly with the increase of the inlet airflow temperature when βb is 8° and 16°, while the thrust coefficient, pitching moment coefficient and lift coefficient have little fluctuation as βb is 12°. The study of the combined effects of the inlet airflow temperature and upper expansion angle on the performance of the scramjet nozzle can provide guidance for the design of scramjet nozzles.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-02
      DOI: 10.1108/AEAT-08-2021-0237
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • The omnidirectional runway with infinite heading as a futuristic runway
           concept for future free route airspace operations

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      Authors: Emre Aydoğan , Soner Demirel
      Abstract: The purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations. This paper researches and analyses the new generated runway concept with the fast time simulation method. Fuel consumption and environmental effect of the new runway system are calculated based on simulation results. According to different traffic density analyses the Omnidirectional Runway with Infinite Heading (ORIH) reduced fuel consumption and CO2 emissions up to 46.97%. Also the total emissions of the ORIH concept, for the hydro carbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) pollutants were lower than the total emissions with the conventional runway up to 83.13, 74.36 and 51.49%, respectively. Free route airspaces bring many advantages to air traffic management and airline operations. Direct routes become available from airport to airport thanks to free route airspace concept. However, conventional single runway structure does not allow aircraft operations for every direction. The landing and take-off operations of a conventional airport with a single runway must be executed with only two heading direction. This limitation brings a bottleneck direct approach and departure route usage as convenient with free route airspace concept. This paper suggests and analyzes the omnidirectional runway with infinite heading (ORIH) as a solution for free route airspace. This paper suggests a new and futuristic runway design and operation for the free route operations. This paper has its originality from the suggested and newly created runway system.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-02
      DOI: 10.1108/AEAT-09-2021-0283
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Schlieren imaging investigation on azimuthally varying shock net from
           four-lobed corrugated nozzle

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      Authors: Kriparaj K.G. , Roy V. Paul , Tide P.S. , Biju N.
      Abstract: The purpose of this paper is to conduct an experimental investigation on the shock cell structure of jets emanating from a four-lobed corrugated nozzle using Schlieren imaging technique. The Schlieren images were captured for seven different nozzle pressure ratios (NPR = 2, 3, 4, 5, 6, 7 and 8) and compared with the shock cell structure of a round nozzle with an identical exit area. The variation in the length of the shock cell, width of boundary interaction between adjacent shock cells, maximum width of first shock cell, Mach disk position and diameter for different NPR was measured from the Schlieren images and analysed. A three-layer shock net observed in the jet emanating from the four-lobed corrugated nozzle is a novel concept in the field of under-expanded jet flows. A shock net represents interconnected layers of shock cells developed because of the interaction between the core and peripheral shock waves in a jet emanating from a corrugated lobed nozzle. Also, the pattern of shock net is different while taking Schlieren images across the groove and lobe sections. Thus, the shock net emerging from a corrugated lobed nozzle varies azimuthally and primarily depends on the nozzle exit cross section. The length of the shock cell, width of boundary interaction between adjacent shock cells, maximum width of first cell, Mach disk position and diameter were found to exhibit increasing trend with NPR. A novel concept of interconnected layers of shock waves defined as “shock net” developed from a single jet emanating from a four-lobed corrugated nozzle was observed.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-03-01
      DOI: 10.1108/AEAT-09-2021-0294
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Systematic design of nonlinear ADRC for laser seeker system with
           FPGA-based rapid prototyping validation

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      Authors: Abdellah Ferdjali , Momir Stanković , Stojadin Manojlović , Rafal Madonski , Dimitrije Bujaković , Abderraouf Djenadbia
      Abstract: A laser seeker is an important element in missile guidance and control systems, responsible for target detection and tracking. Its control is, however, a challenging problem due to complex dynamics and various acting disturbances. Hence, the purpose of this study is to propose a systematic design, tuning, analysis and performance verification of a nonlinear active disturbance rejection control (ADRC) algorithm for the specific case of the laser seeker system. The proposed systematic approach of nonlinear ADRC application to the laser seeker system consists of the following steps. The complex laser seeker control problem is first expressed as a regulation problem. Then, a nonlinear extended state observer (ESO) with varying gains is used to improve the performance of a conventionally used linear ESO (LESO), which enables better control quality in both transient and steady-state periods. In the next step, a systematic observer tuning, based on a detailed analysis of the system disturbances, is proposed. The stability of the overall control system is then verified using a describing function method. Next, the implementation of the NESO-based ADRC solution is realized in a fixed-point format using MATLAB/Simulink and Xilinx System Generator. Finally, the considered laser seeker control system is implemented in discrete form and comprehensively tested through hardware-in-the-loop (HIL) co-simulation. Through the conducted comparative study of LESO-based and NESO-based ADRC algorithms for the laser seeker system, the advantages of the proposed nonlinear scheme are shown. It is concluded that the NESO-based ADRC scheme for the laser seeker system (with appropriate parameters tuning methodology) provides better control performance in both transient and steady-state periods. The conducted multicriteria study validates the efficacy of the proposed systematic approach of applying nonlinear ADRC to laser seeker systems. In practice, the obtained results imply that the laser seeker system, governed by the studied nonlinear version of the ADRC algorithm, could potentially detect and track targets faster and more accurately than the system based on the common linear ADRC algorithm. In addition, the article presents the step-by-step procedure for the design, field programmable gate array (FPGA) implementation and HIL-based co-simulation of the proposed nonlinear controller, which can be used by control practitioners as one of the last validation stages before experimental tests on a real guidance system. The main contribution of this work is the systematic procedure of applying the ADRC scheme with NESO for the specific case of the laser seeker system. It includes its design, tuning, analysis and performance verification (with simulation and FPGA hardware). The novelty of the work is also the combination and practical realization of known theoretical elements (NESO structure, NESO parameter tuning, ADRC closed-loop stability analysis) in the specific case of the laser seeker system. The results of the conducted applied research increase the current state of the art related to robust control of laser seeker systems working in disturbed and uncertain conditions.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-02-25
      DOI: 10.1108/AEAT-06-2021-0188
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Improvement of aircraft maintenance manual (AMM) for Cessna 172

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      Authors: Tarik Gunes , Ugur Turhan , Birsen Yörük Açıkel
      Abstract: This study aims to bring a new approach to the existing structure of Cessna 172 type Aircraft Maintenance Manuals (AMM), operational safety, suitability for maintenance operations and human factors. The purpose of this study is to maintain maintenance operations more safely and effectively. This study tried to develop an approach by using focus group interview and individual interview techniques. At all stages of the study, interviews were made and support was received from the maintenance technicians, technical instructors and students from the aviation industry stakeholders. According to the answers given by the participants, the new approach could have a positive effect on operational safety (98.71%), could have a positive effect on human performance (95.72%) it is understandable (93.16%), it is proper for maintenance operations (88.74%) with high potential to convert into practice (85.92%) and a high potential for future applications (97.06%). It can be used in aviation organizations that operate AMM Cessna 172 type aircraft, created with the new approach, in maintenance aircraft maintenance enterprises and maintenance training institutions. Thanks to this approach, aircraft maintenance technicians will be able to perform safely and more effective maintenance activities. Contrary to the technologies used by organizations that host wide-body aircraft in their fleets, it requires less cost and less workload to create, use and update. Low-cost airline organizations and maintenance training institutions will also be able to achieve this approach.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-02-23
      DOI: 10.1108/AEAT-10-2021-0321
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • Dynamic model to characterise sectors using machine learning techniques
         This is an Open Access Article Open Access Article

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      Authors: Francisco Pérez Moreno , Víctor Fernando Gómez Comendador , Raquel Delgado-Aguilera Jurado , María Zamarreño Suárez , Dominik Janisch , Rosa María Arnaldo Valdes
      Abstract: The purpose of this paper is to set out a methodology for characterising the complexity of air traffic control (ATC) sectors based on individual operations. This machine learning methodology also learns from the data on which the model is based. The methodology comprises three steps. Firstly, a statistical analysis of individual operations is carried out using elementary or initial variables, and these are combined using machine learning. Secondly, based on the initial statistical analysis and using machine learning techniques, the impact of air traffic flows on an ATC sector are determined. The last step is to calculate the complexity of the ATC sector based on the impact of its air traffic flows. The results obtained are logical from an operational point of view and are easy to interpret. The classification of ATC sectors based on complexity is quite accurate. The methodology is in its preliminary phase and has been tested with very little data. Further refinement is required. The methodology can be of significant value to ATC in that when applied to real cases, ATC will be able to anticipate the complexity of the airspace and optimise its resources accordingly.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-01-20
      DOI: 10.1108/AEAT-11-2021-0330
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2022)
       
  • An effort saving method to establish global aerodynamic model using CFD
         This is an Open Access Article Open Access Article

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      Authors: Jingfeng Xie , Jun Huang , Lei Song , Jingcheng Fu , Xiaoqiang Lu
      Abstract: The typical approach of modeling the aerodynamics of an aircraft is to develop a complete database through testing or computational fluid dynamics (CFD). The database will be huge if it has a reasonable resolution and requires an unacceptable CFD effort during the conceptional design. Therefore, this paper aims to reduce the computing effort required via establishing a general aerodynamic model that needs minor parameters. The model structure was a preconfigured polynomial model, and the parameters were estimated with a recursive method to further reduce the calculation effort. To uniformly disperse the sample points through each step, a unique recursive sampling method based on a Voronoi diagram was presented. In addition, a multivariate orthogonal function approach was used. A case study of a flying wing aircraft demonstrated that generating a model with acceptable precision (0.01 absolute error or 5% relative error) costs only 1/54 of the cost of creating a database. A series of six degrees of freedom flight simulations shows that the model’s prediction was accurate. This method proposed a new way to simplify the model and recursive sampling. It is a low-cost way of obtaining high-fidelity models during primary design, allowing for more precise flight dynamics analysis.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2022-04-26
      DOI: 10.1108/AEAT-10-2021-0299
      Issue No: Vol. 94 , No. 11 (2022)
       
  • Performance of a microjet using component map scaling

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      Authors: Kahraman Coban , Selcuk Ekici , Can Ozgur Colpan , Tahir Hikmet Karakoç
      Abstract: This paper aims to investigate the cycle performance of a small size turbojet engine used in unmanned aerial vehicles at 0–5,000 m altitude and 0–0.8 Mach flight speeds with real component maps. The engine performance calculations were performed for both on-design and off-design conditions through an in-house code generated for simulating the performance of turbojet engines at different flight regimes. These calculations rely on input parameters in which fuel composition are obtained through laboratory elemental analysis. Exemplarily, according to comparative results between in-house developed performance code and commercially available software, there is 0.25% of the difference in thrust value at on-design conditions. Once the on-design performance parameters and fluid properties were determined, the off-design operation calculations were performed based on the compressor and turbine maps and scaling methodology. This method enables predicting component maps and fitting them to real conditions. A method to be used easily by researchers on turbojet engine performance calculations which best fits to real conditions.
      Citation: Aircraft Engineering and Aerospace Technology
      PubDate: 2021-08-05
      DOI: 10.1108/AEAT-02-2021-0056
      Issue No: Vol. ahead-of-print , No. ahead-of-print (2021)
       
  • Aircraft Engineering and Aerospace Technology

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