Archives of Thermodynamics最新文献_第2页

Comparative thermo-hydraulic analysis of periodic stepped open micro pin-fin heat sink 周期性阶梯开放式微型针翅散热器的热液压对比分析

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151228

P. Bhandari, Bhavesh Vyas, Diwakar Padalia, Lalit Ranakoti, Y. Prajapati, Raghubeer S. Bangari

{"title":"Comparative thermo-hydraulic analysis of periodic stepped open micro pin-fin heat sink","authors":"P. Bhandari, Bhavesh Vyas, Diwakar Padalia, Lalit Ranakoti, Y. Prajapati, Raghubeer S. Bangari","doi":"10.24425/ather.2024.151228","DOIUrl":"https://doi.org/10.24425/ather.2024.151228","url":null,"abstract":"There is no doubt that the miniaturization of various electronic devices, including processors, servers, micro-electromechan-ical system devices, etc. has resulted in increased overall performance. However, there is a major problem with thermal management in these devices, as well as in many others. One of the most promising solutions is liquid cooled microchannel heat sink. In the current work, different cases of open micro pin-fin configurations of heat sink were considered. The con-figurations considered were a uniform height micro pin-fin heat sink, three-stepped unidirectional micro pin-fin heat sink and three-stepped bi-directional micro pin-fin heat sink. These configurations were also oriented in two dissimilar fashions, i.e. inline and staggered, so the total of six heat sink configurations are compared and analysed. Using single phase water as a coolant and copper as a substrate, these configurations were simulated numerically for different Reynolds numbers (10−160) under heat flux of 500 kW/m2. It can be concluded that at low Reynolds numbers, steepness does not contribute much in both inline and staggered arrangements, while at higher Reynolds numbers, 3 stepped staggered configurations has revealed the best performance due to boosted fluid mixing and more projecting secondary flow. Furthermore, bi-direction-ality in steepness shows augmented performance only in inline arrangement.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141653125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CFD analysis of the effect of bed geometry on H2O adsorption and desorption efficiency 床层几何形状对 H2O 吸附和解吸效率影响的 CFD 分析

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151214

Szymon Janusz, Marcin Borcuch, Piotr Cyklis

{"title":"CFD analysis of the effect of bed geometry on H2O adsorption and desorption efficiency","authors":"Szymon Janusz, Marcin Borcuch, Piotr Cyklis","doi":"10.24425/ather.2024.151214","DOIUrl":"https://doi.org/10.24425/ather.2024.151214","url":null,"abstract":"The article presents a comprehensive computational fluid dynamics analysis of the adsorption and desorption cycles in adsorption refrigeration systems, focusing on the impact of the adsorbent bed geometry. The entire adsorption/desorption cycle has been modeled, allowing for the observation of events during the transitional period between processes and how these influence their progression. This approach is a novelty in the field. The developed numerical model was verified against experimental data available in the literature, demonstrating excellent convergence with the experiment, with a de-viation not exceeding 2%. The study illustrates how the geometrical parameters such as height and length of the bed affect the efficiency of the adsorption and desorption processes, emphasizing the importance of bed geometry in the adsorption of heat and mass exchangers in energy and adsorbate transfer. The research findings provide valuable insights for designing more efficient cooling devices using adsorption technology, highlighting the role of bed geometry in optimizing these systems. Modeling the entire adsorption/desorption cycle is a novelty and allows for the observation of what happens during the transitional period between processes and how this influences their progression.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling of heat transfer during flow condensation of natural refrigerants under conditions of increased saturation pressure 饱和压力增加条件下天然制冷剂流动冷凝过程中的传热建模

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151215

S. Głuch, D. Mikielewicz

引用次数: 0

Effects of Joule heating due to magnetohydrodynamic slip flow in an inclined channel 倾斜通道中的磁流体滑移流引起的焦耳加热效应

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151219

Jagadeeshwar Pashikanti, Santhosh Thota, Susmitha Priyadharshini

{"title":"Effects of Joule heating due to magnetohydrodynamic slip flow in an inclined channel","authors":"Jagadeeshwar Pashikanti, Santhosh Thota, Susmitha Priyadharshini","doi":"10.24425/ather.2024.151219","DOIUrl":"https://doi.org/10.24425/ather.2024.151219","url":null,"abstract":"Graphene oxide nanoparticles with higher thermal conductivity aid in enhancing the flow and heat transport in magnetohy-drodynamic devices such as magnetohydrodynamic pumps. Modelling such devices with promising applications inherently necessitates entropy studies to ensure efficient models. This investigation theoretically studies the entropy generation in magnetohydrodynamic flow of graphene oxide in an inclined channel. Buongiorno nanofluid model is used including the impacts of nanoparticle attributes, namely thermophoretic and Brownian diffusion along with viscous dissipation effects. The spectral quasi-linearization method with Chebyshev’s polynomials is adapted to solve the differential equations under slip conditions. On studying the effects of implanted parameters, it is concluded that the conductive heat transfer enhancement by the Hartmann number is remarked. The Bejan number is found to be greater than 0.9 and hence, heat transfer primarily causes the entropy generation. A good agreement is found between the results for special cases and the results from the literature. Furthermore, investigations conclude that entropy is contributed primarily by heat transfer.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of entropy generation in unsteady flow of nanofluids past a convectively heated moving permeable cylindrical surface 纳米流体流经对流加热的移动可渗透圆柱表面的非稳态流动中的熵生成分析

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151221

Itumeleng Chokoe, O. Makinde, R. L. Monaledi

引用次数: 0

Flame stabilization and combustion enhancement in a scramjet combustor by varying strut injection angles 通过改变支杆喷射角实现扰流喷气燃烧器的火焰稳定和燃烧增强

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151227

Venkateshwaran Vanamamalai, Padmanathan Panneerselvam

{"title":"Flame stabilization and combustion enhancement in a scramjet combustor by varying strut injection angles","authors":"Venkateshwaran Vanamamalai, Padmanathan Panneerselvam","doi":"10.24425/ather.2024.151227","DOIUrl":"https://doi.org/10.24425/ather.2024.151227","url":null,"abstract":"The present study explores the characteristics of reacting flow in a scramjet combustor with struts, focusing particularly on implementing different injection strategies. A three-dimensional DLR scramjet combustor is utilised to assess the impact on the system, incorporating multiple injections and varying injection angles on the triangular wedge. The analysis considers three injectors with parallel, upward and downward injections at angles of 15° and 30°. The numerical investigation is con-ducted under a constant total pressure of 7.82 bar, a temperature of 340 K, and an airspeed of Mach 2 at the inlet. The results highlight the significance of injector location and shape in promoting flame stabilization. Furthermore, injection angles play a crucial role in mitigating shockwave intensity. The numerical analysis involves a steady-state Reynolds-averaged Navier-Stokes equation with the shear stress transport k–ω turbulence model. The obtained results were analyzed by examining the critical variables such as Mach number, static pressure and combustion efficiency across the combustor. Based on the com-putational results, injecting fuel upward not only increases the overall pressure loss but also enhances the subsonic regime downstream of the strut, which leads to better mixing and combustion efficiencies. This is primarily due to shockwave generation from the edges of the strut and the interactions with the fuel stream shear layers.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141652385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of variable thermal conductivity in semiconducting medium underlying an elastic half-space 弹性半空间底层半导体介质中可变热导率的影响

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151226

P. Ailawalia, Priyanka

引用次数: 0

Phase change material selection for energy storage units using a simple and effective decision-making method 利用简单有效的决策方法为储能装置选择相变材料

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151217

Ravipudi Venkata Rao

{"title":"Phase change material selection for energy storage units using a simple and effective decision-making method","authors":"Ravipudi Venkata Rao","doi":"10.24425/ather.2024.151217","DOIUrl":"https://doi.org/10.24425/ather.2024.151217","url":null,"abstract":"This study provides a simple and effective decision-making method to choose the best phase-change material for different energy storage applications. Three case studies are provided to demonstrate the proposed decision-making method. The first case study addresses the problem of best phase-change material selection for a domestic water heating latent heat storage system by considering 15 different phase-change materials and 8 selection attributes; the second case study addresses the problem of selecting the best phase-change material for a triple tube heat exchanger unit by considering 12 different phase-change materials and 5 selection attributes; the third case study addresses the problem of best phase-change material selection for latent heat thermal energy storage within the walls of Trombe to enhance performance considering 11 phase-change materials and 4 selection attributes. The results of the proposed decision-making method are compared with those of other well-known multi-attribute decision-making methods. The proposed method is shown to be simple to implement, providing a logical way for allocating weights to the selection attributes and adaptable to phase-change material selection problems in different energy storage contexts.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141653968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat flow analysis and description of the cooperation of the heat exchange station with heat exchange substations located in apartments 热流分析及热交换站与位于公寓内的热交换分站的合作说明

IF 0.8

Archives of Thermodynamics Pub Date : 2024-07-12 DOI: 10.24425/ather.2024.151218

D. Taler, T. Sobota, Jan Taler, Agata Kania, Robert Wiśniewski

{"title":"Heat flow analysis and description of the cooperation of the heat exchange station with heat exchange substations located in apartments","authors":"D. Taler, T. Sobota, Jan Taler, Agata Kania, Robert Wiśniewski","doi":"10.24425/ather.2024.151218","DOIUrl":"https://doi.org/10.24425/ather.2024.151218","url":null,"abstract":"This paper presents an analysis of the heat flow in a plate heat exchanger located at a building heat exchange station. The plate heat exchanger is the main source of heat for the building system based on microsubstations in the building apartments. The co-operation of the heat exchange station with the substations in the apartments is also described. Such microstations are intended for both domestic hot water preparation and apartment heating. The method of calculating the product of the heat transfer coefficient k and the heat exchange surface area A is presented. In order to verify the correctness of the measured values of the temperatures of hot and cold water at the heat exchange station inlet and outlet, they were compared to the values calculated using the -NTU method. Good agreement was found between the results of the calculations and the meas-urements. Recommendations were made for the temperature of return water to the heating station. The cost of operating the district heating network could be reduced by increasing the surface area of central heating radiators in apartments, so that the temperature of return water to the heating station could be lowered.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141653015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of the impact of jet impingement technique on the energy efficiency of air-cooled BIPV/T roof tile 评估喷射撞击技术对风冷 BIPV/T 瓦能源效率的影响

IF 0.9

Archives of Thermodynamics Pub Date : 2024-06-06 DOI: 10.24425/ather.2024.150847

Jan Wajs, Jakub Lukasik

{"title":"Assessment of the impact of jet impingement technique on the energy efficiency of air-cooled BIPV/T roof tile","authors":"Jan Wajs, Jakub Lukasik","doi":"10.24425/ather.2024.150847","DOIUrl":"https://doi.org/10.24425/ather.2024.150847","url":null,"abstract":"The paper concerns a numerical analysis of cooling of the hybrid photovoltaic (PV) modules dedicated to Building-Inte-grated Photovoltaic/Thermal (BIPV/T) systems. Attention was focused on the photovoltaic roof tiles, using a jet impinge-ment technique, in which the intensification of heat transfer is ensured by streams of air hitting the heat exchange partition. A series of numerical simulations were carried out to assess an influence of the distance of the nozzle outlet from the absorber surface on the values of selected thermal-hydraulic performance indicators and the electrical parameters of the roof tile. The results confirmed the high effectiveness of the proposed method. The best effect was obtained for the case in which the relative distance of the nozzle from the partition to the nozzle diameter was equal to 1. For the mentioned configuration, an over 4 times increase in the value of the heat transfer coefficient was obtained in relation to the reference variant of cooling roof tiles. At the same time, the relative increase in the value of the generated electrical power was from 2.9 to 7.8%, depending on the value of the Reynolds number characterising the flow.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0