Case Studies in Thermal Engineering最新文献

Employing thermochromic material to improve the building thermal environment in Qingdao city 应用热致变色材料改善青岛市建筑热环境

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-16 DOI: 10.1016/j.csite.2025.106351

Chenxi Hu , Wenkai Fu , Xi Meng , Fan He , Hiroatsu Fukuda

{"title":"Employing thermochromic material to improve the building thermal environment in Qingdao city","authors":"Chenxi Hu , Wenkai Fu , Xi Meng , Fan He , Hiroatsu Fukuda","doi":"10.1016/j.csite.2025.106351","DOIUrl":"10.1016/j.csite.2025.106351","url":null,"abstract":"<div><div>Utilizing novel building envelope materials to mitigate urban heat is an effective measure. Among the many new cooling building materials, cooling coatings are notable for their superior solar reflectance and thermal emissivity, properties that help reduce cooling loads by lowering surface temperatures. However, these static reflective coatings are unable to meet the changing thermal demands in regions with significant seasonal temperature differences, such as hot summers and cold winters. To address this challenge, this study proposes a thermochromic material (TCM) with dynamic self-adjusting reflectivity properties. The TCM is able to change its color and solar reflectivity in response to temperature changes, effectively adapting to the varying thermal demands between winter and summer. In addition, this study evaluated the difference in thermal performance of TCM in summer and winter by conducting experiments on a scaled-down building model. The experiments monitored the external surface temperature, internal surface temperature and cavity temperature, revealing the seasonal energy saving benefits of the TCM. Numerical simulations through Energyplus software further evaluated the heating and cooling degree days and energy carbon emission metrics, providing energy saving directions for optimizing the photo-thermal response properties of thermochromic coatings.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106351"},"PeriodicalIF":6.4,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical and artificial neural network framework for predicating MHD radiative flow and heat transfer of hybrid nanofluid with Cattaneo-Christov theory 基于Cattaneo-Christov理论的混合纳米流体MHD辐射流和传热预测的数值和人工神经网络框架

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-14 DOI: 10.1016/j.csite.2025.106311

Fathi Alimi , Sohail Rehman , Mohamed Bouzidi , Fisal Asiri , Taoufik Saidani , Vineet Tirth

{"title":"Numerical and artificial neural network framework for predicating MHD radiative flow and heat transfer of hybrid nanofluid with Cattaneo-Christov theory","authors":"Fathi Alimi , Sohail Rehman , Mohamed Bouzidi , Fisal Asiri , Taoufik Saidani , Vineet Tirth","doi":"10.1016/j.csite.2025.106311","DOIUrl":"10.1016/j.csite.2025.106311","url":null,"abstract":"<div><div>In this paper, the artificial neural network (ANN) is executed to scrutinize the heat transfer performance of water-based hybrid nanofluid (HNF) flow over a permeable stretching surface under the influence of an inclined magnetic field and thermal radiation. The advanced Cattaneo–Christov heat flux model (CCHFM), is introduced in this study in order to characterize the heat transfer features in a boundary layer (BL) slip flow, with thermal radiation, variable thermal conductivity and nanoparticles diffusion. The equation of energy is renovated taking thermal radiation, variable thermal conductivity, thermal jump and thermal relaxation effects. The flow model is constructed using BL approximation and necessary assumption while the Robin type boundary conditions are obtained by assuming thermal jump and velocity slip. The modified first order differential equations are solved using Bvp4c mechanism. The findings reveals that the coefficient of frictional drag is reduced by the magnetic parameter while contrary behavior is seen for nanoparticle volume fraction. The precision of the ANN model appeared astounding, with an error range of 10 <span><math><mrow><msup><mi>E</mi><mrow><mo>−</mo><mn>8</mn></mrow></msup></mrow></math></span> to 10 <span><math><mrow><msup><mi>E</mi><mrow><mo>−</mo><mn>9</mn></mrow></msup></mrow></math></span>. The regression values that are nearer 1 indicate a good fit between the actual data and the forecasts. The thermal relaxation parameter diminished the temperature and heat dissipation.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106311"},"PeriodicalIF":6.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Large eddy simulations of pool fires and backdraft in a compartment using FDS and FireFOAM 使用FDS和FireFOAM模拟隔间内池火和回流的大涡流

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-14 DOI: 10.1016/j.csite.2025.106337

Dinesh Myilsamy , Chang Bo Oh , Joonho Jeon

{"title":"Large eddy simulations of pool fires and backdraft in a compartment using FDS and FireFOAM","authors":"Dinesh Myilsamy , Chang Bo Oh , Joonho Jeon","doi":"10.1016/j.csite.2025.106337","DOIUrl":"10.1016/j.csite.2025.106337","url":null,"abstract":"<div><div>This study evaluated the performance of two widely used fire simulation codes for predicting heptane pool fires and methane backdrafts occurring within a compartment. The simulation models used were Fire Dynamics Simulator (FDS), which applies a low-Mach-number approximation, and FireFOAM, which performs a compressible flow analysis. Turbulence analysis was conducted using the large eddy simulation (LES) technique. The eddy dissipation model (EDM) was applied to pool fire simulations, and the eddy dissipation concept (EDC) model, which considers a two-step chemical reaction, was applied to backdraft simulations. Both simulation codes reasonably predicted the temperature and key chemical species, such as O<sub>2</sub> and CO<sub>2</sub> concentrations, for the heptane pool fire, with FDS predicting slightly higher temperatures than FireFOAM. For methane backdrafts, both models performed similarly during the gravity current phase; however, significant differences were observed in backdraft onset and propagation. FireFOAM closely matched the experimental pressure data, whereas FDS overestimated the pressure and predicted an earlier peak. FireFOAM also simulates flame distribution and fireball formation more reasonably. FDS, which uses a low-Mach-number approximation, is computationally efficient but less accurate for backdrafts, where pressure changes are crucial.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106337"},"PeriodicalIF":6.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A fully coupled thermal-fluid-electric-mechanics multiphysics numerical model for comprehensive performance evaluation of annular thermoelectric generators 环形热电发电机综合性能评价的热-流-电-力全耦合多物理场数值模型

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-14 DOI: 10.1016/j.csite.2025.106329

Ding Luo , Zheng Li , Ying Li , Haokang Zhang , Xuehui Wang

{"title":"A fully coupled thermal-fluid-electric-mechanics multiphysics numerical model for comprehensive performance evaluation of annular thermoelectric generators","authors":"Ding Luo , Zheng Li , Ying Li , Haokang Zhang , Xuehui Wang","doi":"10.1016/j.csite.2025.106329","DOIUrl":"10.1016/j.csite.2025.106329","url":null,"abstract":"<div><div>The maximum thermal stress is an important indicator for evaluating the thermal reliability of thermoelectric generators (TEGs), but theoretical models to simultaneously predict the thermoelectric and thermomechanical performance of TEGs are lacking. Therefore, a fully coupled thermal-fluid-electric-mechanics multiphysics numerical model is established, and it is adopted to conduct a comprehensive numerical analysis of an annular TEG. Additionally, the influences of geometric parameters (height <em>h</em> and angle <span><math><mrow><mi>θ</mi></mrow></math></span>) of thermoelectric elements and exhaust conditions on the performance of the annular TEG are studied. Numerical results reveal that reducing the thermoelectric element height (<em>h</em>) from 5 mm to 2 mm under <em>T</em><sub>in</sub> = 550 K and <em>ṁ</em><sub>ex</sub> = 30 g/s enhances output power by 27.6 % (10.97 W–14.02 W) but lowers conversion efficiency from 3.41 % to 2.99 %, while maximum thermal stress decreases by 11.6 % (289.72 MPa–256.07 MPa). Increasing the angle (<em>θ</em>) from 4° to 7° elevates output power by 11.6 % (12.94 W–14.44 W) yet reduces efficiency by 14.4 % (3.34 %–2.86 %), with thermal stress amplified for larger <em>θ</em>–<em>θ</em><sub>s</sub> mismatches. Both the thermoelectric and thermomechanical performance of the annular TEG are more significantly affected by exhaust temperature compared to mass flow rate. This model integrates fluid dynamics and thermal-electric-mechanics coupling, overcoming limitations of prior studies that simplified boundary conditions. It provides actionable insights for optimizing annular TEGs in automotive waste heat recovery, balancing thermoelectric performance and thermomechanical performance.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106329"},"PeriodicalIF":6.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling and performance analysis of a solar thermal desalination system using simulation in TRNSYS software 利用TRNSYS仿真软件对太阳能热脱盐系统进行建模和性能分析

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-14 DOI: 10.1016/j.csite.2025.106332

Mohammad Shykhaee, Hossein Yousefi, Ahmad Hajinezhad, Mahmood Abdoos, Younes Noorollahi

{"title":"Modeling and performance analysis of a solar thermal desalination system using simulation in TRNSYS software","authors":"Mohammad Shykhaee, Hossein Yousefi, Ahmad Hajinezhad, Mahmood Abdoos, Younes Noorollahi","doi":"10.1016/j.csite.2025.106332","DOIUrl":"10.1016/j.csite.2025.106332","url":null,"abstract":"<div><div>Solar energy is one of the clean and sustainable solutions to fight freshwater scarcity in hot and arid regions. The current paper presents the design of a thermal desalination system powered by solar energy for large-scale freshwater production by using the TRNSYS software. Solar collectors' Energy supply accounts for saline Water's required phase change, with a six-stage separator to extract the generated steam from saline Water. More precisely, heat exchangers condense the generated steam and heat the feeding saline water before the solar collectors are in place. Further, the concerned simulation has taken the meteorological data from Bandar Abbas due to high solar irradiation and its closeness with seawater from the Persian Gulf. Consequently, the computer-based simulated results highlighted that on occasions of maximum solar radiation, the solar collector exit temperature reached approximately 190 °C. However, in the case of the temperature increase of the water required to produce steam, it takes quite some time; hence, on the ground, this installation operates about 6 h a day despite the available 10-h active solar radiation. On a day like that, 470,000 m<sup>3</sup> of Freshwater would have been produced, whereas on one of the hottest weeks during the whole year in late May, it is very confident of showing a yield of 45 %. The system's efficiency was also calculated to be 43 %, even on the year's coldest days. A short comparison with other available studies further confirmed the system's effectiveness. Therefore, this research highlights solar energy's viability as a renewable and clean approach to solving water shortage problems in hot and arid regions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106332"},"PeriodicalIF":6.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transient response of a hygrothermoelastic cylinder with internal heat and moisture sources using non-Fourier hyperbolic coupled model 利用非傅立叶双曲耦合模型研究具有内部热源和湿源的湿热弹性圆柱体的瞬态响应

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-14 DOI: 10.1016/j.csite.2025.106207

Y. Peng , X.Y. Zhang , X.F. Li

引用次数: 0

In situ performances of direct absorption solar collector based on Ag NPs-rGO hybrid nanofluid Ag - NPs-rGO混合纳米流体直接吸收太阳能集热器的原位性能研究

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-13 DOI: 10.1016/j.csite.2025.106330

Angel Huminic, Gabriela Huminic

{"title":"In situ performances of direct absorption solar collector based on Ag NPs-rGO hybrid nanofluid","authors":"Angel Huminic, Gabriela Huminic","doi":"10.1016/j.csite.2025.106330","DOIUrl":"10.1016/j.csite.2025.106330","url":null,"abstract":"<div><div>Recent research on direct absorption solar collectors (DASCs) follows a general upward trend due to continuous development of new materials and working fluids, which provide opportunities for improvement of their performances regarding conversion of solar energy into thermal energy. Using of nanofluids as absorbent and heat-conducting media has proven to be an efficient method to increase the effectiveness of these collectors, mainly due to higher optical properties, particularly absorption, compared to typical working fluids, e.g. water, ethylene-glycol or oil, which absorb weakly the sunlight. In this study, a DASC prototype has been designed and optimized using CFD, and later fabricated and tested using Ag NPs + rGO hybrid nanofluid in water-ethylene glycol solution. To evaluate the effect of the nanoparticles, experiments were simultaneously carried out for two DASCs, the second one being filled with simple water-ethylene glycol solution, and used also as reference DASC. In order to achieve relevant data, the investigations were performed under outdoor conditions during summer season, for several representative flow rates of the working fluid. The results show that the efficiency of DASC using hybrid nanofluid increases significantly, the maximum relative enhancement being 74.1 %. In addition, instantaneous and accumulative energies delivered are about 44 % and 98 % respectively higher than for DASC using water-ethylene glycol solution. Based on data collected, a correlation for Nusselt number is proposed.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106330"},"PeriodicalIF":6.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the suppressive effects of carbon dioxide on coal dust explosions: Experimental and simulation discussion 二氧化碳对煤尘爆炸的抑制作用研究：实验与模拟讨论

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-13 DOI: 10.1016/j.csite.2025.106321

Bingyou Jiang , Jing-Jing Li , Mingqing Su , Kunlun Lu , Qi Yao , Xuerong Liang

{"title":"Study on the suppressive effects of carbon dioxide on coal dust explosions: Experimental and simulation discussion","authors":"Bingyou Jiang , Jing-Jing Li , Mingqing Su , Kunlun Lu , Qi Yao , Xuerong Liang","doi":"10.1016/j.csite.2025.106321","DOIUrl":"10.1016/j.csite.2025.106321","url":null,"abstract":"<div><div>This study systematically investigates the effectiveness and mechanism of CO<sub>2</sub> in suppressing coal powder explosions from both macroscopic and microscopic perspectives. Experimental and kinetic modeling results reveal that the explosion pressure of coal powder decreases with increasing CO<sub>2</sub> volume fraction, with an effective suppression concentration of 15 %. CO<sub>2</sub> enhances the thermal stability of coal powder, raising the activation energy of the combustion stage from 72.577 kJ/mol to 76.541 kJ/mol. In addition, the microstructure and predominant forms of the solid explosion products show that CO<sub>2</sub> effectively suppresses the breakage of carbon chain structures and the release of CH<sub>4</sub> and other gases during coal powder explosions. It also significantly suppresses the formation of C-O and hydroxyl-<em>π</em> functional groups, with their relative contents decreasing by 28.29 % and 10.43 %, respectively. This is consistent with the numerical simulation results, which show a decrease of 0.048 mole/cm<sup>3</sup>·s in the total OH production rate, clearly identifying the key step in the chain reaction blocked by CO<sub>2</sub>: H + O<sub>2</sub> → OH + O. This establishes the suppression mechanism of CO<sub>2</sub> on coal powder explosions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106321"},"PeriodicalIF":6.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DFT insights into double transition metal M2M’SiC2 MAX Phases: Prospects as thermal barrier coatings 双过渡金属M2M的sic2max相的DFT分析：作为热障涂层的前景

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-13 DOI: 10.1016/j.csite.2025.106334

Ahmed Azzouz-Rached , Mohammed Traiche , Abdessalem Bouhenna , Nasir Rahman , Mudasser Husain , Ali Bentouaf , Amani H. Alfaifi , Wafa Mohammed Almalki , Hind Albalawi , Khamael M. Abualnaja , Eman Almutib , Hamza Rekab-Djabri , Mamoun Fellah

{"title":"DFT insights into double transition metal M2M’SiC2 MAX Phases: Prospects as thermal barrier coatings","authors":"Ahmed Azzouz-Rached , Mohammed Traiche , Abdessalem Bouhenna , Nasir Rahman , Mudasser Husain , Ali Bentouaf , Amani H. Alfaifi , Wafa Mohammed Almalki , Hind Albalawi , Khamael M. Abualnaja , Eman Almutib , Hamza Rekab-Djabri , Mamoun Fellah","doi":"10.1016/j.csite.2025.106334","DOIUrl":"10.1016/j.csite.2025.106334","url":null,"abstract":"<div><div>The exceptional properties of MAX phases in the quaternary group (M<sub>2</sub>M'SiC<sub>2</sub>) have garnered significant scientific and technological interest due to their unique combination of metallic and ceramic-like characteristics. To gain deeper insights into the properties of these compounds, researchers have utilized Density Functional Theory (DFT). The computational investigations confirm their robust stability, as evidenced by strong mechanical stability criteria and negative formation energies, indicating thermodynamic favorability. Additionally, the phonon dispersion curves of these materials reveal the absence of imaginary frequencies, aligning with theoretical predictions and confirming their dynamical stability. These compounds are found to be ductile, characterized by a predominantly ionic bonding nature. Moreover, Cr<sub>2</sub>VSiC<sub>2</sub> and V<sub>2</sub>CrSiC<sub>2</sub> exhibit remarkable thermal properties, including high melting and Debye temperatures, which enhance their potential for high-temperature applications. Electronic structure analysis further reveals that M<sub>2</sub>M'SiC<sub>2</sub> compounds with hexagonal symmetry exhibit metallic behavior, making them suitable for applications that demand excellent electrical conductivity alongside mechanical resilience. These findings highlight the potential of M<sub>2</sub>M'SiC<sub>2</sub> MAX phases for innovative applications in industries requiring materials that combine strength, thermal stability, and metallic conductivity.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"72 ","pages":"Article 106334"},"PeriodicalIF":6.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Centerline temperature distribution of compartment spray fire under limited ceiling ventilation 有限顶棚通风条件下隔间喷雾火灾的中心线温度分布

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2025-05-13 DOI: 10.1016/j.csite.2025.106322

Fangpeng Guo , Changjian Wang

引用次数: 0