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  Subjects -> ENGINEERING (Total: 2417 journals)
    - CHEMICAL ENGINEERING (207 journals)
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    - ELECTRICAL ENGINEERING (111 journals)
    - ENGINEERING (1267 journals)
    - ENGINEERING MECHANICS AND MATERIALS (400 journals)
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ENGINEERING (1267 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 8)
3D Research     Hybrid Journal   (Followers: 21)
AAPG Bulletin     Hybrid Journal   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 14)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 274)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 7)
Advanced Journal of Graduate Research     Open Access  
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 5)
Advanced Science Letters     Full-text available via subscription   (Followers: 10)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 13)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 29)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in OptoElectronics     Open Access   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 44)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 3)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 6)
AIChE Journal     Hybrid Journal   (Followers: 35)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 26)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 10)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 24)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 4)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Antarctic Science     Hybrid Journal   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 18)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 11)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 3)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 5)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Motor Trade Survey     Full-text available via subscription  
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Beyond : Undergraduate Research Journal     Open Access  
Bhakti Persada : Jurnal Aplikasi IPTEKS     Open Access  
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Bilge International Journal of Science and Technology Research     Open Access  
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 11)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 21)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 37)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal   (Followers: 1)
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 40)
Bitlis Eren University Journal of Science and Technology     Open Access  
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 13)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal   (Followers: 2)
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 31)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 42)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Thermal Engineering     Open Access   (Followers: 5)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal  
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 3)
CienciaUAT     Open Access   (Followers: 1)
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 13)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
Clinical Science     Full-text available via subscription   (Followers: 9)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 6)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 14)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 28)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Composite Structures     Hybrid Journal   (Followers: 278)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 212)
Composites Part B : Engineering     Hybrid Journal   (Followers: 248)
Composites Science and Technology     Hybrid Journal   (Followers: 195)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access   (Followers: 1)
Computational Geosciences     Hybrid Journal   (Followers: 16)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computers & Geosciences     Hybrid Journal   (Followers: 31)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 8)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 5)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 7)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 33)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)

        1 2 3 4 5 6 7 | Last

Journal Cover
Case Studies in Thermal Engineering
Journal Prestige (SJR): 0.991
Citation Impact (citeScore): 3
Number of Followers: 5  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2214-157X
Published by Elsevier Homepage  [3163 journals]
  • Some solar passive concepts in habitat through natural ventilation case
           study: Dry climate in Algeria Ghardaia

    • Authors: M.K. Cherier; T. Benouaz; S.M.A. Bekkouche; M. Hamdani
      Pages: 1 - 7
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): M.K. Cherier, T. Benouaz, S.M.A. Bekkouche, M. Hamdani
      The main objective of this paper is to study the effect of one of the most important negative concepts through natural ventilation as an economical solution and an inexpensive health phenomenon. Ventilation of buildings is a commitment and requires a minimum of flue that must be guaranteed to avoid discomfort. Air leakage in heated space increased incoming flow rates. Therefore, the leakage in the envelope building plays a major role in thermal losses. Loss created by air exchange system. So experts stressed that opening and closing windows provides a way to control the outside air in all cases. Through the daily programming schedule by climate and region, for example Ghardaia. The area of Ghardaia features characteristics of a high temperature zone especially for the months May to October. This period is characterized by climate and is often hot and in our case with habitat to strong thermal inertia of it can generate discomfort. In this case the thermal inertia is not suitable. Therefore, no other solution of ventilation night becomes more important in hot weather.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.02.002
      Issue No: Vol. 12 (2018)
       
  • Studies on energy consumption of crude oil pipeline transportation process
           based on the unavoidable exergy loss rate

    • Authors: Qinglin Cheng; Anbo Zheng; Lu Yang; Chenlin Pan; Wei Sun; Yang Liu
      Pages: 8 - 15
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Qinglin Cheng, Anbo Zheng, Lu Yang, Chenlin Pan, Wei Sun, Yang Liu
      In order to ensure the crude oil pipeline process smoothly, the driving force has a certain exergy loss. Based on the exergy analysis method, according to the required minimum potential difference of pipeline transportation, the unavoidable exergy loss is defined in the process. In order to reflect the real effective utilization degree of energy consumption, the unavoidable exergy loss rate is put forward as the evaluation index. And it is calculated by the ratio of related the unavoidable exergy loss and the exergy loss. The crude oil pipeline exergy loss rate is calculated under different conditions. The orthogonal experiment analysis used to compare the influence degree of different operating parameters on the pipeline unavoidable exergy loss rate show that the influence degree on the unavoidable exergy loss rate in turn is: outbound temperature, flow and outbound pressure. It also provide the reference for the energy-saving transportation of crude oil pipeline.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.02.005
      Issue No: Vol. 12 (2018)
       
  • Carreau fluid flow in a thermally stratified medium with heat
           generation/absorption effects

    • Authors: Khalil Ur Rehman; Ali Saleh Alshomrani; M.Y. Malik
      Pages: 16 - 25
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Khalil Ur Rehman, Ali Saleh Alshomrani, M.Y. Malik
      In this article theoretical attempt is carried to inspect the flow field characteristics of Carreau fluid model. The fluid flow is achieved by stretching cylindrical surface with no slip condition that is the relative velocity of Carreau fluid particles and cylindrical surface is zero. The role of both temperature stratification and heat generation/absorption are considered with the source of energy equation. The physical illustration of flow model with both temperature stratification and heat generation/absorption effects is translated in terms of partial differential equations through fundamental laws, namely law of conservation of mass, momentum and energy. The obtained partial differential equations are non-linear in nature and it seems difficult to solve them analytically. Therefore the boundary layer approximation is utilized to retain the active parts of flow narrating differential equations. Then to step down the partial differential equations in terms of ordinary differential equations a set of transformations is introduced. The reduced system is solved by shooting method and self-coded algorithm is executed in this regard. The note down observations are offered with the aid of graphs and tables. It is noticed that the Carreau fluid temperature shows decline nature towards the positive values of thermal stratification parameter and heat absorption parameter but it reflects opposite trend for the case of heat generation parameter.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.001
      Issue No: Vol. 12 (2018)
       
  • An integrated program of a stand-alone parabolic trough solar thermal
           power plant: Code description and test

    • Authors: Sanan T. Mohammad; Hussain H. Al-Kayiem; Morteza K. Assadi; Osama. Sabir; Ayad K. Khlief
      Pages: 26 - 37
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Sanan T. Mohammad, Hussain H. Al-Kayiem, Morteza K. Assadi, Osama. Sabir, Ayad K. Khlief
      Solar thermal systems produce steam after being energized by solar parabolic trough concentrators, are incorporated with a steam turbine-generator assembly to produce electricity. This study presents a code for prediction of performance, while under-taking preliminary plant-sizing for a variety of parabolic trough solar fields operating under nominal conditions. The code, named as PTPPPP (Parabolic Trough Power Plant Performance Predictor) consists of four blocks. The code allows prediction of variables including: heat loss coefficient, U L , aperture effective direct normal irradiance, I, heat gain, Q gain , and the thermal efficiency of stand-alone parabolic trough solar thermal power plant in commerce, ηp. The conceptual design of the stand-alone parabolic trough solar involves: selection and sizing of system components, power generation cycles, working fluid types, and power block sizing. The input weather parameters and the operational parameters to the code have been acquired from in-situ measurements. The prediction results of the code have been found in good agreement with literature data with mean error of 0.18% in prediction of output power. In addition, this code is able to provide a flexibility in terms of temperature, heat transfer, and pressure range.
      Graphical abstract image

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.02.006
      Issue No: Vol. 12 (2018)
       
  • On the conceptual design of the novel balanced rolling piston expander

    • Authors: Antonio Giuffrida; Gianluca Valenti; Davide Palamini; Luigi Solazzi
      Pages: 38 - 46
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Antonio Giuffrida, Gianluca Valenti, Davide Palamini, Luigi Solazzi
      This work presents a novel type of positive-displacement expander, named the balanced rolling piston expander. It proposes also a design procedure and assesses the mechanical behavior of a virtual prototype. The expander is conceptually capable of operating at higher fluid temperatures than other positive-displacement expanders, such as scroll- or screw-type machines. Moreover, it employs a radially balanced rotor, differently from common rolling piston technologies and does not require any timing mechanism for filling and emptying the working chambers, differently from Wankel or reciprocating solutions. The investigated virtual prototype is chosen for the study case of a small-scale heat recovery unit currently under investigation. The results indicate that a prototype of about 300 mm in diameter and 100 mm in length is capable of an ideal power of 20 kW. Moreover, vane accelerations can be relatively high but anyhow comparable to those in sliding vane machines, while pressure drops in percent terms are in general lower than 1%. Lastly, load-induced displacements are manageable by a proper radial clearance at room temperature. In brief, the balanced rolling piston expander is a promising option for small-scale power generation units operating with temperatures not achievable by common technologies and, hence, it deserves further investigation.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.003
      Issue No: Vol. 12 (2018)
       
  • Influence of mechanical smoke exhaust on smoke spread in underground
           tunnel

    • Authors: Hai jun Tao; Guoqing Zhu; Yu Xia; Yongchang Zhao
      Pages: 47 - 54
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Hai jun Tao, Guoqing Zhu, Yu Xia, Yongchang Zhao
      The model of a tunnel in Beijing is established, and the smoke reflux, the smoke reflux length and the influence of longitudinal wind speed on temperature distribution of the tunnel vault are studied using numerical simulation method. The length of the tunnel is 150 m, the cross section is circular, the height of the tunnel is 6.3 m and the width is 6 m. The simulation results show that the smoke reflux length of the subway tunnel fire decreases with the increase of the longitudinal positive pressure wind speed, and the reflux length decreases linearly with the increase of wind speed when the reflux length is more than 10 m. The gradient of the reflux length decreases with the increase of the wind speed when the distance from the fire source decreases. The temperature curve of tunnel vault is consistent. Under the same fire source heat release rate, the flue gas temperature decreases with the increase of ventilation wind speed, and the distance between the highest temperature of the ceiling and the fire source decreased with the increase of the longitudinal ventilation wind speed.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.02.003
      Issue No: Vol. 12 (2018)
       
  • Exhaust noise, performance and emission characteristics of spark ignition
           engine fuelled with pure gasoline and hydrous ethanol gasoline blends

    • Authors: Xiaokang Deng; Zhenbin Chen; Xiaochen Wang; Haisheng Zhen; Rongfu Xie
      Pages: 55 - 63
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Xiaokang Deng, Zhenbin Chen, Xiaochen Wang, Haisheng Zhen, Rongfu Xie
      The exhaust noise, performance and emission characteristics of a gasoline engine fuelled by hydrous ethanol gasoline with 10%, 20% hydrous ethanol by volume (E10W and E20W) and pure gasoline (E0) were experimentally investigated. The tests were performed at full load and different engine speeds varying from 1500 rpm to 5000 rpm. The results showed that compared with E0, E10W and E20W had much lower exhaust noise at low engine speeds. With the increase of engine speed, E0 showed an advantage in low exhaust noise. However, engine fuelled with three fuels displayed comparable noise emissions at high speed. In addition, better thermal efficiency, significantly decreased CO and HC emissions were achieved by hydrous ethanol gasoline at all tested operating conditions. However, significant NOx emission and slight BSFC were observed for E10W and E20W. Compared with E20W, E10W showed decreased BSFC, HC and NOx emissions with the increase of engine speed, while CO emission was only slightly increased. Hydrous ethanol gasoline was capable of realizing comparable torque and power with E0 at all operating conditions. From the results above, hydrous ethanol gasoline could be considered as a promising alternative for SI engine. What's more, E10W exhibits enhanced performance.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.02.004
      Issue No: Vol. 12 (2018)
       
  • Case study on thermal impact of novel corrosion inhibitor on mild steel

    • Authors: Hussein Jwad Habeeb; Hasan Mohammed Luaibi; Thamer Adnan Abdullah; Rifaat Mohammed Dakhil; Abdul Amir H. Kadhum; Ahmed A. Al-Amiery
      Pages: 64 - 68
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Hussein Jwad Habeeb, Hasan Mohammed Luaibi, Thamer Adnan Abdullah, Rifaat Mohammed Dakhil, Abdul Amir H. Kadhum, Ahmed A. Al-Amiery
      Just a few investigations have studied the function of various temperatures in distribution system mild steel corrosion. Generally, increasing temperatures caused the accelerated corrosion of mild steel. In addition, the average of chemical processes were increased as the temperatures were increased regarding to Arrhenius' Law. The synthesis and characterization of a novel organic corrosion inhibitor 4-(((5-ethyl-1,3,4-thiadiazol-2-yl) imino) methyl) phenol, for mild steel in hydrochloric acid was successfully reported for the first time. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution using Potentio-dynamics (PD) and Electrochemical Frequency Modulation (EFM) method. The results obtained indicate that inhibitor acts as an excellent corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the results parameters suggested adsorption on the surface of mild steel sample, which it leading to the formation of protective coating layer. However, this protective layer becomes weak when the temperature of the solution increases.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.005
      Issue No: Vol. 12 (2018)
       
  • Experimental study on smoke temperature distribution under different power
           conditions in utility tunnel

    • Authors: Yong-chang Zhao; Guo-qing Zhu; Yun-ji Gao
      Pages: 69 - 76
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Yong-chang Zhao, Guo-qing Zhu, Yun-ji Gao
      The longitudinal and cross-sectional temperature distributions are measured in reduced-scale tunnel fire experiments with different fire power conditions. Field tests are carried out in a utility tunnel with pool fires. The experiments studied the ceiling temperature along the tunnel centerline, the vertical temperature below the ceiling and the temperature in the direction of radian in the same section with the fire source. The results from the burning experiments are analyzed. The longitudinal temperature distribution along the tunnel can be fairly well fitted by exponential equations. And the thermal radiation of the smoke layer has a significant effect on the temperature below the ceiling. In addition, in the direction of tunnel radian, the temperature growth rate of the region above 45° are obviously faster and the temperature is higher. Therefore, to shorten the response time of the detector to the fire, it is desirable to place the heat and smoke detectors at the top of the utility tunnel.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.002
      Issue No: Vol. 12 (2018)
       
  • Experimental and theoretical research on the fire safety of a building
           insulation material via the ignition process study

    • Authors: Yufeng Huang; Yufeng Li
      Pages: 77 - 84
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Yufeng Huang, Yufeng Li
      A series of experiments were carried out on extruded polystyrene (XPS) foam using a vertical thermal radiator. Measurements were taken for the ignition time, the pyrolysis mass and the temperature distribution. Two kinds of XPS foam with flame retardant levels of B1 and B2 were tested in the experiments and the incident heat fluxes were set as 20, 30, 35, 40, 50 and 60 kW/m2. For the XPS shrinks to a thin layer under the thermal radiator heating, thus the classical ignition theory may be improper and the new functions relationship between the ignition time and the radiant heat flux was derived in theory and experiment. What's more, the pyrolysis mass increases with the radiant heat flux, while the extent of increasing reduces as the radiant heat flux increases. And the result of temperature distribution indicated that under high incident heat flux the flame retardant treatment becomes less effective. The research results were useful for the theory and the experimental study on the fire characteristic of foamed polymer under vertical radiation condition.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.008
      Issue No: Vol. 12 (2018)
       
  • Forecasting the heating and cooling load of residential buildings by using
           a learning algorithm “gradient descent”, Morocco

    • Authors: Alaoui Sosse Jihad; Mohamed Tahiri
      Pages: 85 - 93
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Alaoui Sosse Jihad, Mohamed Tahiri
      In this study, the main objective is to predict the energy needs of residential buildings in the climate zone of Agadir, Morocco, benefitting from orientation, relative compactness, glazing rate, wall surface area, the height and the surface area of the building by using artificial neural networks (ANN) as a learning algorithm. The training data of the neural network were produced using parametric analysis giving rise to 5625 samples in accordance with the mode of construction and use of residential buildings. For each building, it is assumed that the angles of orientation of the samples vary from 0° to 180°, the glazing rates were chosen between 5% and 45%, the heights between 3.5 and 17.5 m and with 25 possible building areas. Three residential buildings "Economic Villa, Economical Construction and Medium Class building" were selected as test data for the neural network model. The Design Builder tool was used for energy demand calculations and a computer program written in Python is used for predictions. As a conclusion; When comparing the calculated values with the outputs of the network, it is proved that the ANN gives satisfactory results with an accuracy of 98.7% and 97.6% for the prediction and test data respectively.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.006
      Issue No: Vol. 12 (2018)
       
  • Combined heat loss analysis of trapezoidal shaped solar cooker cavity
           using computational approach

    • Authors: Jayashree Nayak; Mohit Agrawal; Saumyakanta Mishra; Sudhansu S. Sahoo; Ranjan K. Swain; Antaryami Mishra
      Pages: 94 - 103
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Jayashree Nayak, Mohit Agrawal, Saumyakanta Mishra, Sudhansu S. Sahoo, Ranjan K. Swain, Antaryami Mishra
      The present paper focuses on computational approach to analyze the heat loss due to natural convection and radiation in a trapezoidal shaped solar cooker. Heat losses due to forced convection and radiation are considered from the top glass cover. The results are verified with standard procedure. Radiative heat loss from the cavity is found to be dominant mode which contributes around 70–80% of the total heat loss. Parametric studies regarding heat loss from the cavity are studied by varying cavity depths, heat transfer coefficients based on the wind speed above the glass surface, emissivity of the plate. Based on different parameters, flow pattern and isotherms inside the cavity have been analyzed. Results are obtained in non-dimensional forms for more generic use and correlation between the total average Nusselt number and its influencing parameters has been formulated for the considered solar cooker cavity.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.009
      Issue No: Vol. 12 (2018)
       
  • Numerical thermodynamic model of alpha-type Stirling engine

    • Authors: Khaled M. Bataineh
      Pages: 104 - 116
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Khaled M. Bataineh
      The objective of this study is to develop accurate practical thermodynamic model for alpha-type Stirling engine with Ross Yoke mechanism. Thermal, pumping, and regeneration loses are considered in developing the thermodynamic model. Two methods for solving the governing equations are proposed. The model is used to predict the power output, and the thermal efficiency. The proposed model is validated against experimental data available from the General Motor GPU-3 Stirling engine prototype. Parametric study is used to investigate the effect of geometric and operation parameters on the engine performance. The effect of regenerator effectiveness, the dead volume ratio, regenerator thermal conductivity, and the heat source temperature, the swept volume ratio on the maximum on engine performance are evaluated. It is found that significant improvement on engine performance can be achieved by optimizing geometric and operating parameters.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.010
      Issue No: Vol. 12 (2018)
       
  • Numerical simulation of fluid solid coupling heat transfer in tunnel

    • Authors: Du Cuifeng; Bian Menglong
      Pages: 117 - 125
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Du Cuifeng, Bian Menglong
      In order to obtain the fluid solid coupling heat transfer law of the roadway, the coupled heat transfer between rock and air is analyzed through Fluent, Steady-State Thermal and Static Structural module in ANSYS. The heat flux and thermal strain of rock and the influence of air which under different wind speed and inlet temperature are obtained. The heat flux in the rock is approximately uniformly distributed in the circular ring shape, and the distribution of the heat flux from high to low is as follows: the roadway wall > rock mass > air. The heat flux of the rock near the wall is greater than that in the far side wall. The maximum is located at the wall, and the value is 160 W/m2. The thermal strain of rock is greatly influenced by local heat source, and the maximum value is 5.1 × 10−5 m/m–1 in of rock is greatly influenced by local heat source, and the maximum valin of rock is greatly influenced by local heat source, and the maximum val. Compared with the loader, the hydrothermal water which has greater influence on the temperature of rock and wind can be regarded as the focus on the control of heat damage.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.007
      Issue No: Vol. 12 (2018)
       
  • Thermal and concentration aspects in Carreau viscosity model via wedge

    • Authors: Usman Ali; Khalil Ur Rehman; Ali Saleh Alshomrani; M.Y. Malik
      Pages: 126 - 133
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Usman Ali, Khalil Ur Rehman, Ali Saleh Alshomrani, M.Y. Malik
      The current pagination reports both the heat and mass transfer aspects subject to two dimensional steady flow over a moving wedge for the Carreau viscosity model with infinite shear rate viscosity. The results are reported for the both shear thinning and shear thickening cases. The set of ordinary differential equations has been obtained by transforming the nonlinear partial differential equations (manipulating fluid flow) with the aid of admissible transformation and then sorted out numerically by using the Runge-Kutta Fehlberg method merged with shooting proficiency. The Carreau fluid temperature reduces via higher values of viscosity ratio parameter for shear thickening case while Carreau fluid concentration shows decline towards wedge angle for both shear thinning and thickening cases.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.007
      Issue No: Vol. 12 (2018)
       
  • Experimental and numerical studies on ceiling maximum smoke temperature
           and longitudinal decay in a horseshoe shaped tunnel fire

    • Authors: Yunji Gao; Guoqing Zhu; Sinian Gu; Haijun Tao; Yongchang Zhao
      Pages: 134 - 142
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Yunji Gao, Guoqing Zhu, Sinian Gu, Haijun Tao, Yongchang Zhao
      The present paper investigates the ceiling maximum smoke temperature and longitudinal decay in tunnel fires using a horseshoe shaped 1:3.7 scale-model tunnel constructed by concrete and a full-scale model tunnel established by SIMTEC for the first time. The maximum smoke temperature beneath the ceiling and the longitudinal temperature profiles were obtained and analyzed. The major conclusions are summarized as follows: The ceiling maximum smoke temperature rise right above the fire source is directly proportional to the terms of Q 2 / 3 / H f 5 / 3 and the ceiling maximum smoke temperature decreases as a sum function of two exponential equations of horizontal distance. Modified equations are proposed for maximum smoke temperature rise beneath the ceiling and longitudinal temperature decay, and the predictions show a good agreement with the values measured by experiments and numerical simulations. The results obtained by numerical simulations agree well with experimental results, and SIMTEC is reasonable to simulate the tunnel fires to predict the temperature profiles. The results are of important significance for tunnel fire safety and personnel evacuation.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.003
      Issue No: Vol. 12 (2018)
       
  • Heat release analysis and thermal efficiency of a single cylinder diesel
           dual fuel engine with gasoline port injection

    • Authors: Chondanai Vipavanich; Sathaporn Chuepeng; Sompol Skullong
      Pages: 143 - 148
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Chondanai Vipavanich, Sathaporn Chuepeng, Sompol Skullong
      Cleaner diesel engines have been successively developed to meet a compromised solution for issues concerning performance and emission regulation. Combustion and exhaust gas after-treatment technologies are exhaustively settled to resolve those problems. A key improvement of the emissions is diesel dual fuel combustion that increases operating range of the premixed combustion. The main aim of this work is to explore the heat release, fuel consumption, and thermal efficiency of a single cylinder diesel dual fuel engine. An intake port fuel injection of gasoline with the flow rates between 0 and 0.06 g/s was accomplished to form a premixed charge prior to induction into the combustion chamber and ignition by the main diesel fuel. The engine was operated on medium load at 1700 rpm without exhaust gas recirculation. An engine indicating system composed of a cylinder pressure transducer and a shaft encoder was used to investigate combustion characteristics based on the first law of thermodynamics. The combustion of higher gasoline pre-mixer increased heat release rates, shortened combustion duration, and increased maximum cylinder pressure than neat diesel combustion. Increasing gasoline proportion reduced the diesel fuel and total fuel consumptions. This enhanced the engine thermal efficiency over the diesel baseline combustion.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.011
      Issue No: Vol. 12 (2018)
       
  • Mathematical modeling and simulation of a solar agricultural dryer with
           back-up biomass burner and thermal storage

    • Authors: Elieser Tarigan
      Pages: 149 - 165
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Elieser Tarigan
      Solar drying is a cost-effective and environmentally friendly method for drying agricultural products. To design a proper solar dryer for specific products, thermodynamic relations for the dryer system need to be considered. Numerical simulations are commonly used for the design and operational control of dryers. This study presents the mathematical modeling and simulation of a solar agricultural dryer with back-up biomass burner and thermal storage. Thermodynamic and numerical simulations of the solar collector and drying chamber are performed, while back-up heater (biomass burner) operation is simulated with a computational fluid dynamics (CFD) simulation. For the solar collector, it was found that the presence of a glass cover significantly increases the temperature of the collector; however, increasing the number of glass covers from one to two does not significantly affect the temperature. Variation in thickness of the back insulation has negligible effects, especially for thicknesses over 3 cm. The results show that there is a small difference in temperature between the bottom three trays, while the temperature on the top tray is significantly higher. The CFD simulation showed that the average drying air temperature in the drying chamber was 56 °C, which is suitable for the drying of agricultural products.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.012
      Issue No: Vol. 12 (2018)
       
  • New advancement of high performance for a combined cycle power plant:
           Thermodynamic analysis

    • Authors: M.N. Khan; I. Tlili
      Pages: 166 - 175
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): M.N. Khan, I. Tlili
      A great amount of energy gets lost through the exhaust of simple, reheat and inter-cooling cycle. Sometimes, this energy is enough to run another cycle or can be used to heat the compressed air from the compressor to the combustion chamber which leads to an increase in the overall efficiency of the plant. Combined cycle is an alternative to utilize the lost energy. In this way, not only the efficiency of the plant increases but it also helps to reduce air pollution and global warming. This paper is a parametric analysis conducted in order to optimize the performance of combined cycle which involves the bypass valve. The result shows that gain in network output is about 45% when the temperature at the inlet of the turbine of topping cycle increases from 1000 K to 1400 K. The gain in net efficiency of the cycle is from 15% to 31% when the temperature at the inlet of the turbine of topping cycle increases from 1000 K to 1400 K. The bypass valve should be opened for small compression ratio and closed for high value of compression ratio.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.001
      Issue No: Vol. 12 (2018)
       
  • Nonlinear thermal radiation effect on magneto Casson nanofluid flow with
           Joule heating effect over an inclined porous stretching sheet

    • Authors: S.S. Ghadikolaei; Kh. Hosseinzadeh; D.D. Ganji; B. Jafari
      Pages: 176 - 187
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): S.S. Ghadikolaei, Kh. Hosseinzadeh, D.D. Ganji, B. Jafari
      In this paper, mixed convection on MHD flow of casson nanofluid over a non-linearly permeable stretching sheet has been investigated and analyzed numerically. The effects of thermal radiation, chemical reaction, heat generation/absorption, viscous dissipation, suction and Joule heating are considered. The Brownian motion and thermophoresis phenomenon are used to model nanoparticles (Buongiorno's model). After converting PDEs governing the problem to ODEs, they have been solved by Runge-Kutta Fehlberg fourth-fifth order method. Obtained results of investigating the effects of different parameters changes on velocity, temperature, and concentration profiles are reported as diagrams. Fluid flow velocity reduction by increase in Hartman number (magnetic field parameter) is due to existence of Lorentz drag force against flow, flow velocity reduction due to increase in casson fluid parameter, increase in temperature profile due to increase in radiation parameter, and nanoparticle concentration profile reduction due to increase in chemical reaction parameter are some of valuable obtained results. Also, in final section of this paper effects of different parameters on skin friction coefficient, local Nusselt and Sherwood numbers are investigated that positive and ascending behavior for all three are reported.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.009
      Issue No: Vol. 12 (2018)
       
  • Effect of cooled EGR on modified light duty diesel engine for combustion,
           performance and emissions under high pressure split injection strategies

    • Authors: Gautam Edara; Y.V.V. Satyanarayana Murthy; Paleti Srinivas; Jayashri Nayar; Merigala Ramesh
      Pages: 188 - 202
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Gautam Edara, Y.V.V. Satyanarayana Murthy, Paleti Srinivas, Jayashri Nayar, Merigala Ramesh
      Environmental concerns demands light duty Engines to satisfy the stringent Euro VI emission norms. The aim of this study is to present the effect of cooled exhaust gas recirculation (EGR) on emission reduction. Tests are conducted on a modified single cylinder light duty diesel engine to run on high pressure common rail direct fuel injection. Diesel is injected directly in to the engine cylinder for both retarded and split injections at pressures of 200, 230, 250, 300 and 350 bar respectively. Cooled EGR is circulated along with intake air in to the inlet manifold of the engine for flow rates of 5% and 10%( wt/wt) of injected air respectively for both retarded and split injections. Single injection is retarded at − 11° ATDC and split injection consists of pilot injection at − 54°ATDC of 10% mass share and main injection at − 11°ATDC of 90% mass share. The result shows split injection (MPFI) decreases the ignition delay, In-cylinder combustion temperature and peak pressure for higher EGR flow rates compared to retarded single injection (SI) for all Injection pressure. Split injection reduced NOx from 1400 ppm to 200 ppm for 10% EGR flow rate at 350 bar injection pressure at full load operating conditions. Split injection at high Injection pressure decreases smoke by 10% as compared to retarded single injection. Test results show that there is trade-off exists between retarded and split injections at 350 bar injection pressure at full load conditions. Retarded injection has 33.61% brake thermal efficiency while split injection exhibits only 29.06% for 5% EGR flow rates. But higher EGR flow rates of 10% both retarded and split injection has nearly same brake thermal efficiency of 30.11%. Split injection reduced the combustion duration, ignition delay and exhaust gas temperatures for higher EGR flow rates compared to single retarded injection. The present research reveals that there exists an injection pressure map between the design operating pressure and maximum injection pressure. MPFI system under CRDI mode is very effective in reducing the NOx emissions with 10% EGR flow rates for maximum Injection pressure. While retarded SI injection is effective for moderate Injection pressure with the same EGR flow rates.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.03.004
      Issue No: Vol. 12 (2018)
       
  • Thermo-physical aspects in tangent hyperbolic fluid flow regime: A short
           communication

    • Authors: Khalil Ur Rehman; Ali Saleh Alshomrani; M.Y. Malik; Iffat Zehra; Muhammad Naseer
      Pages: 203 - 212
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Khalil Ur Rehman, Ali Saleh Alshomrani, M.Y. Malik, Iffat Zehra, Muhammad Naseer
      The present attempt is made to report the flow regime characteristics of tangent hyperbolic fluid when both the magnetic field and heat generation effects are taken into account. The flow narrating differential equations subject to thermally stratified medium are transformed into a system of nonlinear ordinary differential equations. A computational algorithm is developed to offer a numerical solution of the flow problem. The physical outcomes against flow controlling parameters namely, curvature parameter, Weissenberg number, power law index, thermal stratification, heat generation and Prandtl number are discussed and illustrated via graphs and tables. The outcomes are certified by providing comparison with existing literature in a limiting sense.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.014
      Issue No: Vol. 12 (2018)
       
  • Heat transfer phenomena on waste heat recovery of combustion stack gas
           with deionized water in helical coiled heat exchanger

    • Authors: Rithy Kong; Thoranis Deethayat; Attakorn Asanakham; Tanongkiat Kiatsiriroat
      Pages: 213 - 222
      Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Rithy Kong, Thoranis Deethayat, Attakorn Asanakham, Tanongkiat Kiatsiriroat
      Theoretical and experimental studies on waste heat recovery of combustion stack gas and heat transfer phenomena of a fully developed laminar flow of deionized water in vertical helical coils were carried out with coil dimensions: tube diameter to coil diameter , d i / D = 0.04 − 0.06 and pitch to coil diameter, p / D = 0.1 − 0.25 . The calculation of heat transfer data was based on countercurrent flow LMTD method. The result showed that deionized water (DI-water) possessed better heat transfer than that of normal water. The effect of coil pitch, coil diameter, and coiled tube diameter on heat transfer phenomena of helical coils had been discussed and a new set of correlation of heat transfer data was created and it could be found that the results from the correlation agreed well with the experimental data. In addition, the overall heat transfer coefficient between the hot exhaust gas and the heat transfer fluid in the helical coil was also considered. Smaller tube diameter gave better overall heat transfer coefficient at low water-side Reynolds number and when the Reynolds number was over 3500 the bigger tube diameter showed the advantage. Smaller coil diameter seemed to get better overall heat transfer coefficient at low water-side Reynolds number.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.010
      Issue No: Vol. 12 (2018)
       
  • A numerical investigation on ethylene glycol-titanium dioxide nanofluid
           convective flow over a stretching sheet in presence of heat
           generation/absorption

    • Authors: Kh. Hosseinzadeh; F. Afsharpanah; S. Zamani; M. Gholinia; D.D. Ganji
      Pages: 228 - 236
      Abstract: Publication date: Available online 11 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Kh. Hosseinzadeh, F. Afsharpanah, S. Zamani, M. gholinia, D.D. Ganji
      In this article, TiO2-ethylene glycol nanofluid flow over a porous stretching sheet in presence of non-uniform generation or absorption of heat and convective boundary condition is investigated. The concentration of solute is set by the means of an isothermal model of homogeneous-heterogeneous reactions. The governing equations were simplified to ordinary differential equations and solved using Runge-Kutta-Fehlberg shooting method of fifth order. Effects of different variables such as nanoparticle volume fraction, porosity variable, and Schmidt number were studied and the results are graphically presented. The results showed that the stretching rate ratio has inverse effect of velocities in both directions. According to plots, nanoparticle volume fraction as well as convective heat intensity has a direct relation with wall heat flux, in the contrary, heat generation has an inverse effect on it.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.008
      Issue No: Vol. 12 (2018)
       
  • The effect of multi-longitudinal vortex generation on turbulent convective
           heat transfer within alternating elliptical axis tubes with various
           alternative angles

    • Authors: Hasan Najafi Khaboshan; Hamid Reza Nazif
      Pages: 237 - 247
      Abstract: Publication date: Available online 18 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Hasan Najafi Khaboshan, Hamid Reza Nazif
      This study strives for a numerical examination of the turbulent flow and the heat transfer of water fluid flow in the alternating elliptical axis tube under various alternative angles. The purpose of this study is to increase the heat transfer by generating multi-longitudinal vortices along the tube flow. By increasing the rotation angle between pitches, the number of the formed multi-longitudinal vortices caused by the secondary flow increase from four to eight. This increase in the number of the multi-longitudinal vortices causes the cold fluid of the tube centre to have interaction in more paths with the hot fluid close to the wall and be mixed as well. This results in an increase of the heat transfer in this type of tubes. In addition, the results show that an improvement in the mean of average Nusselt numbers of alternating elliptical axis tube with the rotation angles of 40 ° , 60 ° , 80 ° , and 90 ° compared to the circular tube are 7.77%, 14.6%, 16.93%, and 24.42%, respectively. Finally, the correlations of the friction factor and the Nusselt number with the Reynolds number are presented for four AEA tubes with different pitches degree (40 ° , 60 ° , 80 ° , and 90 ° ).

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.013
      Issue No: Vol. 12 (2018)
       
  • Determination of effective moisture diffusivity and thermodynamic
           properties variation of regional wastes under different atmospheres

    • Authors: Fernandez Anabel; Román Celia; Mazza Germán; Rodriguez Rosa
      Pages: 248 - 257
      Abstract: Publication date: Available online 24 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Fernandez Anabel, Román Celia, Mazza Germán, Rodriguez Rosa
      During the thermal process to transform lignocellulosic wastes in energy, the drying process is an important stage because it requires energy and decreases overall process yield. Considering this process, moisture diffusivity is an important factor that is considered essential to understand for design, analysis, and its optimization. In this work, this parameter was analyzed at non-isothermal condition and considering the process under inert and oxidative atmospheres. Lower diffusivities were obtained under low heating rates, due to the disfavoring the moisture diffusion in the particles. Higher effective diffusivity (Deff) values were obtained when the drying is carried out under the atmosphere oxidative. Moreover, the thermodynamic parameters and DTA curves were determined. ∆H values are positive in all cases, showing that the drying process is endothermic. ∆G are positive and ∆S negative, indicating that the process is non-spontaneous. DTA curves show that the drying process is endothermic, according with the calculated ∆H.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.015
      Issue No: Vol. 12 (2018)
       
  • PERFORMANCE EVALUATION AND PARAMETRIC STUDIES ON VARIABLE NOZZLE EJECTOR
           USING R134A

    • Authors: B. Elhub; Sohif Mat; K. Sopian; A.M. Elbreki; Mohd Hafidz Ruslan; A.A. Ammar
      Pages: 258 - 270
      Abstract: Publication date: Available online 13 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): B. Elhub, Sohif Mat, K. Sopian, A.M. Elbreki, Mohd Hafidz Ruslan, A.A. Ammar
      Computational fluid dynamics of variable nozzle ejector has been studied to determine the optimum nozzle exit position for reliable ejector cooling cycle operations. The flow rates of primary and secondary stream were varied to obtain the optimum entrainment ratio under different ranges of operating conditions. The refrigerant R134a was chosen based on the merit of its environmental and performance characteristics, the refrigerant was chosen because currently is used widely in air conditioning system. It was found that the computational fluid dynamics showed that the optimum positioning of nozzle exit position, which was based on the parameters such as pressure inlet variation the temperature inlet. The results obtained after the optimization of the results showed that the optimum nozzle exit position was found at 3mm from the mixing chamber inlet when the operating conditions pressure inlet, secondary pressure inlet, primary temperature inlet and outlet pressure were at ( 18 bar , 6 bar , 373 K , and 5.6 bar ) respectively. Similarly, the range of entrainment ratio was varied between 0.24 − 1.283 at a constant area ratio, and at varied operating conditions.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.006
      Issue No: Vol. 12 (2018)
       
  • Thermal Analysis in Stokes’ Second Problem of Nanofluid:
           Applications in Thermal Engineering

    • Authors: Ilyas Khan; Kashif Ali Abro; M.N. Mirbhar; I. Tlili
      Pages: 271 - 275
      Abstract: Publication date: Available online 10 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Ilyas Khan, Kashif Ali Abro
      Present study is prepared to analyze the heat transfer for the Stokes’ second problem of nanofluid. Water is taken as base fluid and two types of nanoparticles namely copper ( C u ) and silver ( A g ) are suspended in it. Exact solutions for velocity field and temperature distribution have been investigated by utilizing the Laplace transform method and presented in the form simple elementary functions. The results lead to the few facts regarding the effects of rheological and pertinent parameters on the graphical illustrations. Heat transfer is decreased with increasing nanoparticles volume fraction. Hartman number and porosity have opposite effects on fluid motion. This study has several applications in thermal engineering.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.005
      Issue No: Vol. 12 (2018)
       
  • Numerical Evaluation of the Effects of Fire on Steel Connections; Part 1:
           Simulation Techniques

    • Abstract: Publication date: Available online 19 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Rohola Rahnavard, Robert Thomas
      Steel connections are used to connect between beam and column in steel moment frame structures. As of present time, there is a huge lack of understanding of the performance of steel connections and their response to fire especially the uncontrolled fires. Therefore, in this paper, by using a finite element program ABAQUS and with the static analysis of coupled temperature- displacement and to fully understand the behavior of such connection under the fire scenario, developed a temperature-dependent models for different types of steel connections are implemented. Finite Element Analyses (FEA) of selected experimental models are performed to verify the implementation of these models. Fully detailed, field-variable-dependent conductivity element models of the connections are developed, and analyses are performed to determine the effects of heat on the behavior of the materials in the elastic and plastic areas are considered. Moreover, severe deformation in the nonlinear region was investigated.

      PubDate: 2018-06-22T00:47:54Z
       
  • Optical efficiency measurement of solar receiver tubes: A testbed and case
           studies

    • Abstract: Publication date: Available online 15 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Rafael López-Martín, Loreto Valenzuela
      Knowledge of the parabolic-trough collector (PTC) solar receiver performance is essential in solar thermal power plants using this type of collector technology because it is the component responsible for collecting the solar radiation and transferring it in the form of thermal energy to the heat transfer fluid. Its performance depends on two parameters, heat loss and the optical efficiency of the solar receiver tubes. Therefore, the receiver optical efficiency must be known for correct sizing of a PTC solar field. This article presents an outdoor testbed developed to measure the optical efficiency of solar receiver tubes under real solar radiation conditions, including a detailed description of the system developed, working principle, test procedure, and performance results for two sample receiver tubes tested showing proper system functioning.

      PubDate: 2018-06-19T00:05:02Z
       
  • Effect of the particle size of pulverized olive cake on combustion
           parameters in Stirling engine in Morocco

    • Abstract: Publication date: Available online 15 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): N. Rassai, N. Boutammachte, H. El hassani, A. Almers, El Mostapha Boudi, A. Bekraoui
      Morocco is one of the richest countries with olive tree. Annually, about 675,000 t of Olive Cake are produced and injected which leads to damaging the environment especially the groundwater as well as the water table itself. To remedy this problem, and because olive cake has a high caloric value, the idea of this paper comes to valorize this waste through the Stirling engine in order to produce clean energy with low greenhouse emissions. To fulfill this purpose, the impact of the particle size of pulverized olive cake (OC) on the flow behavior and combustion parameters in a 3D vertical chamber was investigated. The spherical OC particles are injected through two injectors perpendicularly to the air inlet jets. Two particle sizes are chosen to conduct this study (PS1, PS2). The numerical approach is based on Reynolds averaged Navier–Stokes (RANS) method using the realizable k–ε turbulence model. For gas phase a non-premixed combustion model is used, and for the discrete second phase a Lagrangian approach is chosen. Temperature distribution, flow topology, velocity contours, and species concentrations profiles in the burner are obtained for the two cases. Results show that the first case particle size gives optimal results and is more suitable for this study.

      PubDate: 2018-06-19T00:05:02Z
       
  • Effect of interfacial thermal resistance and nanolayer on estimates of
           effective thermal conductivity of nanofluids

    • Abstract: Publication date: Available online 13 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Ali Khodayari, Matteo Fasano, Masoud Bozorg Bigdeli, Shahin Mohammadnejad, Eliodoro Chiavazzo, Pietro Asinari
      Colloidal suspensions of nanoparticles (nanofluids) are materials of interest for thermal engineering, because their heat transfer properties are typically enhanced as compared to the base fluid one. Effective medium theory provides popular models for estimating the overall thermal conductivity of nanofluids based on their composition. In this article, the accuracy of models based on the Bruggeman approximation is assessed. The sensitivity of these models to nanoscale interfacial phenomena, such as interfacial thermal resistance (Kapitza resistance) and fluid ordering around nanoparticles (nanolayer), is considered for a case study consisting of alumina nanoparticles suspended in water. While no significant differences are noticed for various thermal conductivity profiles in the nanolayer, a good agreement with experiments is observed with Kapitza resistance ≈ 10 − 9 m2K/W and sub-nanometer nanolayer thickness. These results confirm the classical nature of thermal conduction in nanofluids and highlight that future studies should rather focus on a better quantification of Kapitza resistance at nanoparticle-fluid interfaces, in order to allow bottom up estimates of their effective thermal conductivity.

      PubDate: 2018-06-19T00:05:02Z
       
  • The Energy and Economic Target Optimization of a Naphtha Production Unit
           by Implementing Energy Pinch Technology

    • Abstract: Publication date: Available online 2 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Ali Manizadeh, Ashkan Entezari, Rouhollah Ahmadi
      In this paper, energy pinch analysis is implemented on the Naphtha Production Unit as an operating process plant. It endeavors to approach the current system to the maximum energy recovery (MER) design by providing several scenarios in the heat exchangers network. Furthermore, the economic analysis considering the initial investment and operating costs of the system was conducted in each scenarios to achieve a cost-effective system. The results obtained just from the pinch analysis optimization technique, indicate that reducing the heating and cooling loads do not reduce the total costs. Therefore, two objective optimization of minimization of the levelized cost of product (LCOP) as well as maximization of the overall energy performance of the system are concerned to find out the optimal scenario of the energy network layout. Here, retrofit of the maximum energy recovery design is performed to represent the energetical and economical optimal layout.

      PubDate: 2018-06-03T22:11:34Z
       
  • Numerical study on the effect of operating nanofluids of photovoltaic
           thermal system (PV/T) on the convective heat transfer

    • Abstract: Publication date: Available online 1 June 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Ali H.A. Al-Waeli, Miqdam T. Chaichan, Hussein A. Kazem, K. Sopian, Javad Safaei
      Photovoltaic (PV) collectors are replaced with hybrid photovoltaic thermal (PV/T) systems to establish an electrical and thermal yields. The main function of such design is to provide cooling for the solar cell by absorbing its temperature. This temperature is used for the thermal energy generation of this hybrid design. High electrical and thermal efficiencies are associated with PV/T's. In this study, mathematical analysis was used to examine the effect of the type of nanoparticles added (SiC, CuO, and Al2O3), and the type of base fluids (water, glycerin, and ethylene glycol) on the convection heat transfer of PV/T system. The solar simulator type 'MINI-EESTC' was modified to work as a PV/T was used in the practical part of the study. The numerical results showed the base fluid and the added nanoparticles' thermophysical properties effect on the convective heat transfer and pressure drop. Glycerin showed the maximum pressure drop while water indicated the minimal value. The addition of nano-SiC for the studied base-fluids afforded higher convective heat transfer than nano-CuO and nano-alumina. The validation of the numerical results with the practical one showed a good agreement.

      PubDate: 2018-06-03T22:11:34Z
       
  • Some particular design considerations for optimum utilization of under
           floor heating systems

    • Abstract: Publication date: Available online 30 May 2018
      Source:Case Studies in Thermal Engineering
      Author(s): S. Oubenmoh, A. Allouhi, A. Ait Mssad, R. Saadani, T. Kousksou, M. Rahmoune, M. Bentaleb
      This paper aims at studying the thermal behavior of an under floor heating system via CFD calculations. The results have discussed some important parameters that need to be controlled for an appropriate operation of the system. These parameters include the velocity inside the pipes, inlet temperatures and the patterns of the tubing form. A new parameter to measure the floor thermal homogeneity has been introduced and evaluated. It is found that, generally, the modulated spiral configuration is the best configuration allowing less pressure losses and better thermal homogenization.

      PubDate: 2018-05-31T21:48:29Z
       
  • Detection of ammonia gas by Knudsen thermal force in micro gas actuator

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Ahmadreza Mahyari, M. Barzegar Gerdroodbary, M. Mosavat, D.D. Ganji
      Direct Simulation Monte Carlo (DSMC) method is applied to evaluate the performance of a new micro gas sensor (MIKRA) for mass analysis of ammonia in the rarefied gas. In order to simulate a rarefied gas inside the micro gas detector, Boltzmann equation is applied to obtain high precision results. This study performed comprehensive studies to reveal the main mechanism of force generation and applied this for the analysis of the gas mixture. Our findings show that value of generated Knudsen force significantly varies when the percentage of the NH3 varies in the mixture. According to obtained results, the maximum Knudsen force increases when the fraction of the ammonia decreases. Our findings reveal that the effect of gap size varies with the pressure of the domain. In addition, the increase of temperature gradient from 40 K to 100 K rises the maximum Knudsen force more than 400% on the shuttle arm.

      PubDate: 2018-05-28T20:51:38Z
       
  • Use of parabolic troughs in HVAC applications – Design calculations
           and analysis

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Khaled Chahine, Rabih Murr, Mohamad Ramadan, Hicham El Hage, Mahmoud Khaled
      The present work is concerned with the combination of solar energy systems with HVAC systems. Namely, the objective is finding a way of applying green energy concepts to HVAC systems. Particularly, solar concepts are employed to supply electrical power to HVAC systems. Hence, an innovative concept that permits the use of electrical energy provided by parabolic troughs to drive electrical components of the HVAC system is suggested. Thermal modeling along with governing equations of electricity production from parabolic troughs are presented. Calculations of the electrical power needed for HVAC system, showed that an order of magnitude of energy saving is attainable. Finally, the aforementioned concept was applied on a genuine case in Beirut city. It was shown that four mirrors with a 0.5 efficiency of the storage system are capable to drive the pumps of a HVAC system of a 4-floor building all over the year.
      Graphical abstract image

      PubDate: 2018-05-28T20:51:38Z
       
  • Entropy generation in MHD mixed convection stagnation-point flow in the
           presence of joule and frictional heating

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): M.I. Afridi, M. Qasim, Ilyas Khan, I. Tlili
      This article looks at the second law analysis of MHD boundary layer stagnation-point flow past over linearly stretched sheet. The thermal boundary condition is supposed to be non-isothermal and the effects of friction and Joule heating have been analysed. By using similarity transformations, the model nonlinear partial differential equations in two independent variables are reduced to ordinary differential equations. The numerical techniques, namely shooting and fourth order Runge-Kutta are used to give a numerical solution. An expression for dimensionless entropy generation and Bejan number are obtained and computed using velocity and temperature profiles. The main objective of this article is to analyse the effects of a magnetic parameter, Prandtl number, Eckert number, stretching parameter, mixed convection parameter and dimensionless temperature parameter on the volumetric rate of entropy production and Bejan number. It is found that entropy generation increases with enhancing values stretching parameter and decrease with the increasing values of dimensionless temperature parameter.

      PubDate: 2018-05-28T20:51:38Z
       
  • Influence of thermal contact on heat transfer from glowing firebrands

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Alok Warey
      The influence of thermal contact between a glowing firebrand and the target fuel bed on the resultant heat transfer into the fuel bed was investigated in this study. A zero dimensional (0-D) model for the firebrand coupled to a transient two dimensional (2-D) explicit finite difference model for the fuel bed were used simulate transient heat transfer from a firebrand deposited on a fuel bed. Two firebrand shapes, a disk shaped firebrand in contact with the fuel bed and a cylinder shaped firebrand with a protruding node in contact with fuel bed, were considered. A model was proposed to estimate the thermal contact resistance between the firebrand and the target fuel bed. Heat transfer from a cylinder shaped firebrand with two contact points was also investigated. The model developed in this study provided detailed information on the temperature distribution and thermal penetration depth in the target fuel bed. Predictions made by the model were in qualitative agreement with experimental data reported in the literature. The firebrand thermal contact resistance model presented in this study can be a useful tool to account for variations in firebrand shape and surface irregularities in both the firebrand and the target fuel bed.

      PubDate: 2018-05-28T20:51:38Z
       
  • Magnetically stirring enhanced thermal performance of phase change
           material

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Dao-Yu Sun, Si-Xin Yan, Zhi-Zhu He
      Here we report an active method to enhance the thermal performance of phase change material (PCM) based on magnetically-stirring method. The magnetic bead with small size embedded in the container filled with octadecanol, is driven to rotate by rotating magnetic field, and induce the forced convective heat transfer of the liquid octadecanol. We investigate the impact of rotating magnetic velocity, magnetic bead size, the distance between magnetic bead and rotating permanent magnet on the surface temperature of the simulated heating plate. The experimental results indicated that magnetically stirring obviously improve the heat transfer from liquid phase to solid phase of octadecanol and make simulated heat source keep a lower and smoother temperature platform. We also find that the best condition point could be determined by matching the rotation velocity for the given size of magnetic bead. These results are expected to provide insights into the design and optimization of latent heat thermal energy storage systems.

      PubDate: 2018-05-28T20:51:38Z
       
  • Micropolar nanofluid flow and heat transfer between penetrable walls in
           the presence of thermal radiation and magnetic field

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): M. Alizadeh, A.S. Dogonchi, D.D. Ganji
      Flow and heat transfer of MHD micro-polar nanofluid in a channel with penetrable walls and considering thermal radiation impact are investigated. A similarity transformation is utilized to transmute the governing momentum and energy equations into non-linear ordinary differential equations with the appropriate boundary conditions. The gained non-linear ordinary differential equations are solved by Duan–Rach Approach (DRA). This method allows us to detect a solution without applying numerical methods to evaluate the unspecified coefficients. The impacts of diverse active parameters such as the micro-polar parameter, the magnetic parameter, the volume fraction of nanofluid and the radiation parameter on the velocity and temperature profiles are examined. Furthermore, the value of the Nusselt number is calculated and presented through figures.

      PubDate: 2018-05-28T20:51:38Z
       
  • Lifted flame property and interchangeability of natural gas on partially
           premixed gas burners

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Zhiguang Chen, Chaokui Qin, Pengfei Duan
      The relationship between lifted flames and burner head temperature of partially premixed gas burners supplied by various natural gas sources was investigated, and the application of AGA(American Gas Association) lifting limit for Chinese domestic gas burners was studied. Results showed that lifted flames became more seriously with the burner head temperature decreasing, also with the increase of lift height of flames, it would lead to reduce the burner head temperature, eventually the burner head would reach the thermal equilibrium state which maintained stable flames and temperature. The lifting limit curve of partially premixed gas burners was only one under the same gas source, and it only depended on the burner structures and gas source characteristics, but nothing to do with the burner head temperature. The gas source with lower Wobbe index and calorific value made the burner appearing lifted flame more easily. Comparing with the experiment results and AGA lifting index prediction, it suggested that the limits of AGA lifting index I L≤ 1.10 should be change into I L≤ 1.05 using in China.

      PubDate: 2018-05-28T20:51:38Z
       
  • Magneto-Marangoni nano-boundary layer flow of water and ethylene glycol
           based γ Al2O3 nanofluids with non-linear thermal radiation effects

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): N. Vishnu Ganesh, Ali J. Chamkha, Qasem M. Al-Mdallal, P.K. Kameswaran
      For the first time, a numerical investigation is performed to study the influences of magnetic field on Marangoni boundary layer flow of water and ethylene glycol based γ Al2O3 nanofluids over a flat surface in the presence of non-linear thermal radiation. Experimental based thermo-physical properties and an effective Prandtl number model for γ Al2O3 nanofluids are considered to analyse the Marangoni convection. To study the magnetic field effects, the electric conductivities of both nanoparticles and base fluids are taking into account. Numerical solutions of resulted equations are obtained using fourth order Runge-Kutta method with shooting technique. The combined effect of magnetic parameter with other involved parameters is discussed on velocity and temperature distributions and the local Nusselt number via graphical illustrations.

      PubDate: 2018-05-28T20:51:38Z
       
  • Thermal characteristic research of associated power devices based on
           three-level inverters and power-loss calculation

    • Abstract: Publication date: September 2018
      Source:Case Studies in Thermal Engineering, Volume 12
      Author(s): Shi-Zhou Xu, Chun-Jie Wang, Fang-Li Lin, Xiang-Yu Zhu, Xue Xia
      To reduce the size and improve the power density of three-level inverters, two or more associated power devices are assembled on the same heatsink, which, however, has a great influence on the thermal characteristics of heatsink because of heat accumulation, and is the main cause of thermal faults. The NPC (Neutral Point Clamped) three-level inverter was taken into this paper as a research target and platform. The dynamic power losses of two power devices were calculated firstly according to the working condition and then put into the solid model. Secondly, the thermal characteristics of heatsink with associated power devices on it were analyzed through finite element analysis, and the temperature rise of power devices were studied as well. Finally, the thermal characteristic experiment was conducted on a 1 MW NPC three-level inverter platform, and the results proved the effectiveness of the research method on thermal characteristics of heatsink with associated power devices.

      PubDate: 2018-05-28T20:51:38Z
       
  • CFD-Based Research on Control Strategy of the Opening of Active Grille
           Shutter on Automobile

    • Abstract: Publication date: Available online 23 May 2018
      Source:Case Studies in Thermal Engineering
      Author(s): JiaCheng Li, YaDong Deng, YiPing Wang, Chuqi Su, Xun Liu
      Active Grille Shutter is a very promising technology to improve the performance and fuel economy of automotive engines. The engine room temperature and the automobile aerodynamic resistance should both been considered when controlling the opening of the Active Grille Shutter. A very complete geometric model was built for exterior of an automobile and interior of its engine room at a scale of 1:1 with different openings of the Active Grille Shutter. An aerodynamic drag coefficient variation curve at different grille openings was obtained through simulation analysis, which coincided with the actual aerodynamic drag coefficient. Research was made on the Active Grille Shutter opening control strategy based on computational fluid dynamics method and with radiator's heat dissipating capacity and the automobile aerodynamic drag coefficient as the evaluation parameters. The Active Grille Shutter opening control strategy was obtained, which guarantees that the automobile aerodynamic resistance is the lowest at different travel speeds, and the engine room temperature is within the optimal range.

      PubDate: 2018-05-28T20:51:38Z
       
  • Hybrid Thermal Model of a Synchronous Reluctance Machine

    • Abstract: Publication date: Available online 17 May 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Payam Shams Ghahfarokhi, Ants Kallaste, Anouar Belahcen, Toomas Vaimann, Anton Rassõlkin
      This paper presents a hybrid thermal modeling methodology to analyze the temperature performance of radial flux electrical machines. For this purpose, the 2D finite element model of the active part of the machine is coupled with a lumped parameters thermal circuit of the end-winding region. A synchronous reluctance machine is used to validate the proposed approach. The results from the proposed method are compared with the experimental ones, which are obtained from a prototype machine. The computations show that the 2D FE model underestimates the temperature rise in the machine as it does not account for the power losses in the end-windings. The hybrid model accounts for these losses as well as for the heat dissipation in the end-winding region.

      PubDate: 2018-05-28T20:51:38Z
       
  • Experimental study on upward flame spread characteristics of external
           thermal insulation material under the influence of porosity

    • Abstract: Publication date: Available online 12 May 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Qing xuan Meng, Guo qing Zhu, Miao miao Yu, Zhen huan Liang
      Upward flame spread characteristics over extruded polystyrene (XPS) foams with different porosities has been analyzed through experiments. In this paper, the average flame height and average maximum flame temperature first rise and then drop with increasing porosity, which is affected by the fuel and oxygen competition mechanisms. For P (the porosity of XPS samples) ≤35%, the positive effect of pores plays a dominant role; the average flame height and average maximum flame temperature increase with the increasing porosity. While the negative effect of pores plays a dominant role when P >35%, causing the average flame height and average maximum flame temperature decrease with the increasing porosity. Modeling and experiments were conducted to study the heat flux from flame. The value of radiation is obviously higher than convection through formula derivation and the experimental results have high similarity with the theoretical results.

      PubDate: 2018-05-28T20:51:38Z
       
  • Effect on TEG performance for waste heat recovery of automobiles using MgO
           and ZnO nanofluid coolants

    • Abstract: Publication date: Available online 12 May 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Dhruv Raj Karana, Rashmi Rekha Sahoo
      Present study deals with the theoretical analysis for the performance comparison of automotive waste heat recovery system with EG-W, ZnO and MgO nanofluidas coolants for TEG system. Effects on performance parameters i.e power output, conversion efficiency and circuit voltage of TEG system with exhaust inlet temperature, total area of TEG, Reynolds number and particle concentration of nanofluids for TEG system have been investigated. Theoretical performance analysis revealed enhancement in output power, conversion efficiency and voltage of the TEG system by the MgO nanofluid, followed by ZnO and EG-W coolants. The power output and the conversion efficiency using 1% vol. fraction MgO nanofluid at an inlet exhaust temperature of 500K, were enhanced by 11.38% and 10.95% respectively, as compared to EG-W coolants. The further increase of nanofluid concentration exhibited a progressive effect on output performance of the TEG system. Further analysis shows that there exists an optimal total area of TEGs for maximum output performance of the system. With MgO nanofluid as a coolant, total area of TEGs can be reduced by up to 33% as compared to EG-W, which would bring significant convenience for the arrangement of TEGs and reduce the cost of TEG system.

      PubDate: 2018-05-28T20:51:38Z
       
  • Case Study Of MHD Blood Flow In A Porous Medium With CNTS And Thermal
           Analysis

    • Authors: Asma Khalid; Ilyas Khan; Arshad Khan; Sharidan Shafie
      Abstract: Publication date: Available online 23 April 2018
      Source:Case Studies in Thermal Engineering
      Author(s): Asma Khalid, Ilyas Khan, Arshad Khan, Sharidan Shafie
      This articles deals with unsteady MHD free convection flow of blood with carbon nanotubes. The flow is over an oscillating vertical plate embedded in a porous medium. Both single-wall carbon nanotubes (SWCNTs) and multiple-wall carbon nanotubes (MWCNTs) are used with human blood as base fluid. The problem is modelled and then solved for exact solution using the Laplace transform technique. Expressions for velocity and temperature are determined and expressed in terms of complementary error functions. Results are plotted and discussed for embedded parameters. It is observed that velocity decreases with increasing CNTs volume fraction and an increase in CNTs volume fraction increases the blood temperature, which leads to an increase in the heat transfer rates. A validation of the present work is shown by comparing the current results with existing literature.

      PubDate: 2018-04-25T15:35:24Z
      DOI: 10.1016/j.csite.2018.04.004
       
 
 
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