for Journals by Title or ISSN for Articles by Keywords help
 Subjects -> ENGINEERING (Total: 2266 journals)     - CHEMICAL ENGINEERING (190 journals)    - CIVIL ENGINEERING (181 journals)    - ELECTRICAL ENGINEERING (100 journals)    - ENGINEERING (1197 journals)    - ENGINEERING MECHANICS AND MATERIALS (390 journals)    - HYDRAULIC ENGINEERING (55 journals)    - INDUSTRIAL ENGINEERING (64 journals)    - MECHANICAL ENGINEERING (89 journals) ENGINEERING (1197 journals)                  1 2 3 4 5 6 | Last
 CEAS Space Journal   [SJR: 0.221]   [H-I: 5]   [0 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1868-2510 - ISSN (Online) 1868-2502    Published by Springer-Verlag  [2335 journals]
• Conceptual design of a crewed reusable space transportation system aimed
at parabolic flights: stakeholder analysis, mission concept selection, and
spacecraft architecture definition
• Authors: Roberta Fusaro; Nicole Viola; Franco Fenoglio; Francesco Santoro
Pages: 5 - 34
Abstract: Abstract This paper proposes a methodology to derive architectures and operational concepts for future earth-to-orbit and sub-orbital transportation systems. In particular, at first, it describes the activity flow, methods, and tools leading to the generation of a wide range of alternative solutions to meet the established goal. Subsequently, the methodology allows selecting a small number of feasible options among which the optimal solution can be found. For the sake of clarity, the first part of the paper describes the methodology from a theoretical point of view, while the second part proposes the selection of mission concepts and of a proper transportation system aimed at sub-orbital parabolic flights. Starting from a detailed analysis of the stakeholders and their needs, the major objectives of the mission have been derived. Then, following a system engineering approach, functional analysis tools as well as concept of operations techniques allowed generating a very high number of possible ways to accomplish the envisaged goals. After a preliminary pruning activity, aimed at defining the feasibility of these concepts, more detailed analyses have been carried out. Going on through the procedure, the designer should move from qualitative to quantitative evaluations, and for this reason, to support the trade-off analysis, an ad-hoc built-in mission simulation software has been exploited. This support tool aims at estimating major mission drivers (mass, heat loads, manoeuverability, earth visibility, and volumetric efficiency) as well as proving the feasibility of the concepts. Other crucial and multi-domain mission drivers, such as complexity, innovation level, and safety have been evaluated through the other appropriate analyses. Eventually, one single mission concept has been selected and detailed in terms of layout, systems, and sub-systems, highlighting also logistic, safety, and maintainability aspects.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0131-7
Issue No: Vol. 9, No. 1 (2017)

• A critical review of nanotechnologies for composite aerospace structures
• Authors: Vassilis Kostopoulos; Athanasios Masouras; Athanasios Baltopoulos; Antonios Vavouliotis; George Sotiriadis; Laurent Pambaguian
Pages: 35 - 57
Abstract: Abstract The past decade extensive efforts have been invested in understanding the nano-scale and revealing the capabilities offered by nanotechnology products to structural materials. Integration of nano-particles into fiber composites concludes to multi-scale reinforced composites and has opened a new wide range of multi-functional materials in industry. In this direction, a variety of carbon based nano-fillers has been proposed and employed, individually or in combination in hybrid forms, to approach the desired performance. Nevertheless, a major issue faced lately more seriously due to the interest of industry is on how to incorporate these nano-species into the final composite structure through existing manufacturing processes and infrastructure. This interest originates from several industrial applications needs that request the development of new multi-functional materials which combine enhanced mechanical, electrical and thermal properties. In this work, an attempt is performed to review the most representative processes and related performances reported in literature and the experience obtained on nano-enabling technologies of fiber composite materials. This review focuses on the two main composite manufacturing technologies used by the aerospace industry; Prepreg/Autoclave and Resin Transfer technologies. It addresses several approaches for nano-enabling of composites for these two routes and reports latest achieved results focusing on performance of nano-enabled fiber reinforced composites extracted from literature. Finally, this review work identifies the gap between available nano-technology integration routes and the established industrial composite manufacturing techniques and the challenges to increase the Technology Readiness Level to reach the demands for aerospace industry applications.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0123-7
Issue No: Vol. 9, No. 1 (2017)

• Influence of hydrogen temperature on the stability of a rocket engine
combustor operated with hydrogen and oxygen
• Authors: Stefan Gröning; Justin Hardi; Dmitry Suslov; Michael Oschwald
Pages: 59 - 76
Abstract: Abstract Since the late 1960s, low hydrogen injection temperature is known to have a destabilising effect on rocket engines with the propellant combination hydrogen/oxygen. Self-excited combustion instabilities of the first tangential mode have been found recently in a research rocket combustor operated with the propellant combination hydrogen/oxygen with a hydrogen temperature of 95 K. A hydrogen temperature ramping experiment has been performed with this research combustor to analyse the impact of hydrogen temperature on the self-excited combustion instabilities. The temperature was varied between 40 and 135 K. Contrary to past results found in literature, the combustor was found to be stable at low hydrogen temperatures while increased oscillation amplitudes of the first tangential mode were found at higher temperatures of around 100 K and above, which is consistent with previous observations of instabilities in this combustor. Further analysis shows that hydrogen temperature has a strong impact on the combustion chamber resonance frequencies. By varying the hydrogen injection temperature, the frequency of the first tangential mode is shifted to coincide with the second longitudinal resonance frequency of the liquid oxygen injector. Excitation of combustion chamber pressure oscillations was observed during such events.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0130-8
Issue No: Vol. 9, No. 1 (2017)

• Beacons for supporting lunar landing navigation
• Authors: Stephan Theil; Leonardo Bora
Pages: 77 - 95
Abstract: Abstract Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0132-6
Issue No: Vol. 9, No. 1 (2017)

• Characterization of the supersonic wake of a generic space launcher
• Authors: A.-M. Schreyer; S. Stephan; R. Radespiel
Pages: 97 - 110
Abstract: Abstract The wake flow of a generic axisymmetric space-launcher model is investigated experimentally for flow cases with and without propulsive jet to gain insight into the wake-flow phenomena at a supersonic stage of the flight trajectory which is especially critical with respect to dynamic loads on the structure. Measurements are performed at Mach 2.9 and a Reynolds number Re D  = 1.3 × 106 based on model diameter D. The nozzle exit velocity of the jet is at Mach 2.5, and the flow is moderately underexpanded (p e/p ∞ = 5.7). The flow topology is described based on velocity measurements in the wake by means of particle image velocimetry and schlieren visualizations. Mean and fluctuating mass-flux profiles are obtained from hot-wire measurements, and unsteady wall-pressure measurements on the main-body base are performed simultaneously. This way, the evolution of the wake flow and its spectral content can be observed along with the footprint of this highly dynamic flow on the launcher main-body base. For the case without propulsive jet, a large separated zone is forming downstream of the main body shoulder, and the flow is reattaching further downstream on the afterbody. The afterexpanding propulsive jet (air) causes a displacement of the shear layer away from the wall, preventing the reattachment of the flow. In the spectral analysis of the baseline case, a dominant frequency around St D  = 0.25 is found in the pressure-fluctuation signal at the main-body base of the launcher. This frequency is related to the shedding of the separation bubble and is less pronounced in the presence of the propulsive jet. In the shear layer itself, the spectra obtained from the hot-wire signal have a more broadband low-frequency content, which also reflects the characteristic frequency of turbulent structures convected in the shear layer, a swinging motion (St D  = 0.6), as well as the radial flapping motion of the shear layer (St D  = 0.85), respectively. Moving downstream along the shear layer, spectral content at slightly higher frequencies (St D  < 4) gets more pronounced and can be related to the shear layer instability process and the signature of smaller turbulent structures that appear in the wake.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0134-4
Issue No: Vol. 9, No. 1 (2017)

• Green micro-resistojet research at Delft University of Technology: new
options for Cubesat propulsion
• Authors: A. Cervone; B. Zandbergen; D. C. Guerrieri; M. De Athayde Costa e Silva; I. Krusharev; H. van Zeijl
Pages: 111 - 125
Abstract: Abstract The aerospace industry is recently expressing a growing interest in green, safe and non-toxic propellants for the propulsion systems of the new generation of space vehicles, which is especially true in the case of Cubesat micro-propulsion systems. Demanding requirements are associated to the future missions and challenges offered by this class of spacecraft, where the availability of a propulsion system might open new possibilities for a wide range of applications including orbital maintenance and transfer, formation flying and attitude control. To accomplish these requirements, Delft University of Technology is currently developing two different concepts of water-propelled micro-thrusters based on MEMS technologies: a free molecular micro-resistojet operating with sublimating solid water (ice) at low plenum gas pressure of less than 600 Pa, and a more conventional micro-resistojet operating with liquid water heated and vaporized by means of a custom designed silicon heating chamber. In this status review paper, the current design and future expected developments of the two micro-propulsion concepts is presented and discussed, together with an initial analysis of the expected performance and potential operational issues. Results of numerical simulations conducted to optimize the design of the heating and expansion slots, as well as a detailed description of the manufacturing steps for the conventional micro-resistojet concept, are presented. Some intended steps for future research activities, including options for thrust intensity and direction control, are briefly introduced.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0135-3
Issue No: Vol. 9, No. 1 (2017)

• Verification and validation of a parallel 3D direct simulation Monte Carlo
solver for atmospheric entry applications
• Authors: Paul Nizenkov; Peter Noeding; Martin Konopka; Stefanos Fasoulas
Pages: 127 - 137
Abstract: Abstract The in-house direct simulation Monte Carlo solver PICLas, which enables parallel, three-dimensional simulations of rarefied gas flows, is verified and validated. Theoretical aspects of the method and the employed schemes are briefly discussed. Considered cases include simple reservoir simulations and complex re-entry geometries, which were selected from literature and simulated with PICLas. First, the chemistry module is verified using simple numerical and analytical solutions. Second, simulation results of the rarefied gas flow around a $$70^{\circ }$$ blunted-cone, the REX Free-Flyer as well as multiple points of the re-entry trajectory of the Orion capsule are presented in terms of drag and heat flux. A comparison to experimental measurements as well as other numerical results shows an excellent agreement across the different simulation cases. An outlook on future code development and applications is given.
PubDate: 2017-03-01
DOI: 10.1007/s12567-016-0133-5
Issue No: Vol. 9, No. 1 (2017)

• A new method for optimization of low-thrust gravity-assist sequences
• Authors: V. Maiwald
Abstract: Abstract Recently missions like Hayabusa and Dawn have shown the relevance and benefits of low-thrust spacecraft concerning the exploration of our solar system. In general, the efficiency of low-thrust propulsion is one means of improving mission payload mass. At the same time, gravity-assist maneuvers can serve as mission enablers, as they have the capability to provide “free energy.” A combination of both, gravity-assist and low-thrust propulsion, has the potential to generally improve mission performance, i.e. planning and optimization of gravity-assist sequences for low-thrust missions is a desirable asset. Currently no established methods exist to include the gravity-assist partners as optimization variable for low-thrust missions. The present paper explains how gravity-assists are planned and optimized, including the gravity-assist partners, for high-thrust missions and discusses the possibility to transfer the established method, based on the Tisserand Criterion, to low-thrust missions. It is shown how the Tisserand Criterion needs to be adapted using a correction term for the low-thrust situation. It is explained why this necessary correction term excludes an a priori evaluation of sequences and therefore their planning and an alternate approach is proposed. Preliminary results of this method, by application of a Differential Evolution optimization algorithm, are presented and discussed, showing that the method is valid but can be improved. Two constraints on the search space are briefly presented for that aim.
PubDate: 2017-02-28
DOI: 10.1007/s12567-017-0147-7

• Editorial
• Authors: Hansjörg Dittus
PubDate: 2017-02-09
DOI: 10.1007/s12567-017-0146-8

• Thanks to our Reviewers of the CEAS Space Journal
• PubDate: 2017-01-31
DOI: 10.1007/s12567-017-0144-x

• Cooperative rendezvous between two spacecraft under finite thrust
• Authors: Weiming Feng; Biao Wang; Kun Yang; Di Zhao
Abstract: Abstract Dynamic equations of orbital elements of a modified vernal equinox for a far-distance cooperative rendezvous between two spacecraft were set up in this paper. The process of the far-distance cooperative rendezvous was optimized by a hybrid algorithm combining particle swarm optimization and differential evolution. The convergent costate vectors were obtained and set as the initial values of sequential quadratic programming to search for precise solutions, and the results proved to be stable and convergent. It can be seen from the results that the flight time of the cooperative rendezvous would be largely saved the amplitude of the thrust would be increased if the other conditions are fixed, and the fuel consumption would not be increased. However, the flight time would no longer decrease when the amplitude of the thrust reaches a certain value. In the last section of this paper, cooperative rendezvous and active–passive rendezvous were compared and analyzed, showing the advantages of cooperative rendezvous when the initial conditions are the same.
PubDate: 2017-01-31
DOI: 10.1007/s12567-017-0145-9

• Numerical and experimental analysis of spallation phenomena
• Authors: Alexandre Martin; Sean C. C. Bailey; Francesco Panerai; Raghava S. C. Davuluri; Huaibao Zhang; Alexander R. Vazsonyi; Zachary S. Lippay; Nagi N. Mansour; Jennifer A. Inman; Brett F. Bathel; Scott C. Splinter; Paul M. Danehy
Pages: 229 - 236
Abstract: Abstract The spallation phenomenon was studied through numerical analysis using a coupled Lagrangian particle tracking code and a hypersonic aerothermodynamics computational fluid dynamics solver. The results show that carbon emission from spalled particles results in a significant modification of the gas composition of the post-shock layer. Results from a test campaign at the NASA Langley HYMETS facility are presented. Using an automated image processing of short exposure images, two-dimensional velocity vectors of the spalled particles were calculated. In a 30-s test at 100 W/cm2 of cold-wall heat flux, more than 722 particles were detected, with an average velocity of 110 m/s.
PubDate: 2016-12-01
DOI: 10.1007/s12567-016-0118-4
Issue No: Vol. 8, No. 4 (2016)

• Minimum stiffness criteria for ring frame stiffeners of space launch
vehicles
• Authors: Linus Friedrich; Kai-Uwe Schröder
Pages: 269 - 290
Abstract: Abstract Frame stringer-stiffened shell structures show high load carrying capacity in conjunction with low structural mass and are for this reason frequently used as primary structures of aerospace applications. Due to the great number of design variables, deriving suitable stiffening configurations is a demanding task and needs to be realized using efficient analysis methods. The structural design of ring frame stringer-stiffened shells can be subdivided into two steps. One, the design of a shell section between two ring frames. Two, the structural design of the ring frames such that a general instability mode is avoided. For sizing stringer-stiffened shell sections, several methods were recently developed, but existing ring frame sizing methods are mainly based on empirical relations or on smeared models. These methods do not mandatorily lead to reliable designs and in some cases the lightweight design potential of stiffened shell structures can thus not be exploited. In this paper, the explicit physical behaviour of ring frame stiffeners of space launch vehicles at the onset of panel instability is described using mechanical substitute models. Ring frame stiffeners of a stiffened shell structure are sized applying existing methods and the method suggested in this paper. To verify the suggested method and to demonstrate its potential, geometrically non-linear finite element analyses are performed using detailed finite element models.
PubDate: 2016-12-01
DOI: 10.1007/s12567-016-0126-4
Issue No: Vol. 8, No. 4 (2016)

• Analysis of the laser ignition of methane/oxygen mixtures in a sub-scale
rocket combustion chamber
• Authors: Michael Wohlhüter; Victor P. Zhukov; Joachim Sender; Stefan Schlechtriem
Abstract: Abstract The laser ignition of methane/oxygen mixtures in a sub-scale rocket combustion chamber has been investigated numerically and experimentally. The ignition test case used in the present paper was generated during the In-Space Propulsion project (ISP-1), a project focused on the operation of propulsion systems in space, the handling of long idle periods between operations, and multiple reignitions under space conditions. Regarding the definition of the numerical simulation and the suitable domain for the current model, 2D and 3D simulations have been performed. Analysis shows that the usage of a 2D geometry is not suitable for this type of simulation, as the reduction of the geometry to a 2D domain significantly changes the conditions at the time of ignition and subsequently the flame development. The comparison of the numerical and experimental results shows a strong discrepancy in the pressure evolution and the combustion chamber pressure peak following the laser spark. The detailed analysis of the optical Schlieren and OH data leads to the conclusion that the pressure measurement system was not able to capture the strong pressure increase and the peak value in the combustion chamber during ignition. Although the timing in flame development following the laser spark is not captured appropriately, the 3D simulations reproduce the general ignition phenomena observed in the optical measurement systems, such as pressure evolution and injector flow characteristics.
PubDate: 2016-12-27
DOI: 10.1007/s12567-016-0143-3

• Propulsive jet simulation with air and helium in launcher wake flows
• Authors: Sören Stephan; Rolf Radespiel
Abstract: Abstract The influence on the turbulent wake of a generic space launcher model due to the presence of an under-expanded jet is investigated experimentally. Wake flow phenomena represent a significant source of uncertainties in the design of a space launcher. Especially critical are dynamic loads on the structure. The wake flow is investigated at supersonic ( $$M=2.9$$ ) and hypersonic ( $$M=5.9$$ ) flow regimes. The jet flow is simulated using air and helium as working gas. Due to the lower molar mass of helium, higher jet velocities are realized, and therefore, velocity ratios similar to space launchers can be simulated. The degree of under-expansion of the jet is moderate for the supersonic case ( $$p_\mathrm{e}/p_\infty \approx 5$$ ) and high for the hypersonic case ( $$p_\mathrm{e}/p_\infty \approx 90$$ ). The flow topology is described by Schlieren visualization and mean-pressure measurements. Unsteady pressure measurements are performed to describe the dynamic wake flow. The influences of the under-expanded jet and different jet velocities are reported. On the base fluctuations at a Strouhal number, around $$\mathrm{St}_D \approx 0.25$$ dominate for supersonic free-stream flows. With air jet, a fluctuation-level increase on the base is observed for Strouhal numbers above $$\mathrm{St}_D \approx 0.75$$ in hypersonic flow regime. With helium jet, distinct peaks at higher frequencies are found. This is attributed to the interactions of wake flow and jet.
PubDate: 2016-12-24
DOI: 10.1007/s12567-016-0142-4

• Erratum to: Verification and validation of a parallel 3D direct simulation
Monte Carlo solver for atmospheric entry applications
• Authors: Paul Nizenkov; Peter Noeding; Martin Konopka; Stefanos Fasoulas
PubDate: 2016-11-22
DOI: 10.1007/s12567-016-0141-5

• Applicability of delay tolerant networking to distributed satellite
systems
• Authors: A. Freimann; T. Tzschichholz; M. Schmidt; A. Kleinschrodt; K. Schilling
Abstract: Abstract Currently, a trend towards distributed small satellite missions is emerging using cooperating satellites to achieve joint mission objectives, e.g. for earth observation. Communication is a key feature when cooperation between satellites is desired. Typically those satellite networks are affected by slow data rates, high packet loss and intermittent connectivity. To address these challenges the store-and-forward approach of the delay tolerant networking (DTN) concept is investigated in this article. Network simulations of typical scenarios were carried out and evaluated to derive statements about the applicability of the DTN approach to networks in low earth orbits.
PubDate: 2016-06-22
DOI: 10.1007/s12567-016-0127-3

• Correction and adjusting for the deformation on solar sail
• Authors: Fan Shen; Siyuan Rong; Hualan Zhang; Fujun Peng; Naigang Cui
Abstract: Abstract A research on structural deformation of solar sail was presented. Nonlinear deformation of the sail was discussed, which will cause an additional devastating torque because of the shifting of the center of mass (CM). Finite-element analysis (FEA) method was carried out. In the computation, a correction was brought in, and a gradually increasing load method was presented. A more accurate membrane deformation result was obtained, and the photons pressure on the membrane was corrected. In purpose to guarantee the control ability in the long mission, a lifting mechanism is developed to adjust the large deformation. The lifting motion and result are verified by Abaqus. The research can be used in the solar sail controlling, where a large deformation may occur and an additional torque will disturb the controlling.
PubDate: 2016-06-11
DOI: 10.1007/s12567-016-0128-2

• Robust approximation of image illumination direction in a
segmentation-based crater detection algorithm for spacecraft navigation
• Authors: Bolko Maass
Abstract: Abstract This paper describes an efficient and easily implemented algorithmic approach to extracting an approximation to an image’s dominant projected illumination direction, based on intermediary results from a segmentation-based crater detection algorithm (CDA), at a computational cost that is negligible in comparison to that of the prior stages of the CDA. Most contemporary CDAs built for spacecraft navigation use this illumination direction as a means of improving performance or even require it to function at all. Deducing the illumination vector from the image alone reduces the reliance on external information such as the accurate knowledge of the spacecraft inertial state, accurate time base and solar system ephemerides. Therefore, a method such as the one described in this paper is a prerequisite for true “Lost in Space” operation of a purely segmentation-based crater detecting and matching method for spacecraft navigation. The proposed method is verified using ray-traced lunar elevation model data, asteroid image data, and in a laboratory setting with a camera in the loop.
PubDate: 2016-06-08
DOI: 10.1007/s12567-016-0129-1

• Transformable reflector structure with V-folding rods
• Authors: Sh. Tserodze; J. Santiago Prowald; V. Gogilashvili; K. Chkhikvadze
Abstract: Abstract A new design of space deployable reflector is presented. In particular, we consider closed-chain system (with central network), which as a result of transformation reaches the conical shape. In conformity with the technical specifications, individual parts of the system perform the simultaneous motion in the radial and axial directions. The main motion of the system produced by geometric constraints is studied, i.e., we consider the degree of structural motion. Parametric degrees of freedom caused by technological errors, modes of motion, types of load or deployment velocity are not taken into consideration at this stage. A peculiar feature of the deployable structure presented in the paper is that, as compared with analogous structures, for connecting the sections with one another there is no need of using synchronization devices in both—upper and lower kinematic chains simultaneously. This structural mechanism is a differential lever mechanism, the driving elements of which enable us to obtain the desired law of motion of every characteristic link. The kinematic model represents the whole system. Therefore, we can construct the function of position of the lever mechanism and also the kinematic functions of transmission. For the preliminary investigation of the structure and making possible changes in it, two mathematical models have been constructed by means of the ANSYS software using the Ansys Parametric Design Language. The degrees of freedom of the hinges are simulated in local coordinate systems and are as much as possible approximated to the real model. Calculations are performed for various kinds of loads and appropriate results are obtained.
PubDate: 2016-06-01
DOI: 10.1007/s12567-016-0125-5

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327

Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs