International Communications in Heat and Mass Transfer最新文献

{"title":"A criterion for determining when convection needs to be considered in calculations of solidification/melting in thermal cavities","authors":"V.R. Voller ,&nbsp;I. Vus̆anović","doi":"10.1016/j.icheatmasstransfer.2024.108301","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108301","url":null,"abstract":"<div><div>In general, modeling the solidification/melting in a rectangular cavity requires an accounting of the buoyancy driven fluid motion and associated convective heat transport. This study asks the question—Under what conditions can the contribution of the convective heat transport be ignored? To answer this question, we consider the problem of the solidification of a pure material in a rectangular cavity. Dimensionless governing equations for this problem are obtained. A numerical parametric study is performed, varying the Prandtl number, the Grashof number, thermal diffusivity ratio, scaled wall temperatures, and cavity aspect ratio. For 55 separate cases, steady state predictions of the fraction of solid in the cavity are obtained. These values are compared to steady state solid fraction predictions from a heat conduction alone model, i.e., a model that neglects convection. This analysis leads to a proposal of dimensionless group <span><math><mi>V</mi></math></span> which provides a criterion for when convection is important. We find that when the value of <span><math><mrow><mi>V</mi><mo>≤</mo><mn>4000</mn></mrow></math></span>, calculations based solely on conduction are sufficient.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108301"},"PeriodicalIF":6.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653664","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}

{"title":"Heuristic based physics informed neural network (H-PINN) approach to analyze nanotribology for viscous flow of ethylene glycol and water under magnetic effects among parallel sheets","authors":"Muhammad Naeem Aslam ,&nbsp;Nadeem Shaukat ,&nbsp;Arshad Riaz","doi":"10.1016/j.icheatmasstransfer.2024.108320","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108320","url":null,"abstract":"<div><div>In this article, we have conducted the study for the flow and thermal transfer of magneto-hydrodynamic squeezing nanofluid in the middle of two collateral plates extending to infinity using artificial neural network (ANN). The fluid employed in this research is a combination of Ethylene Glycol and water, and we delve into the utilization of a hybrid nanoparticle consisting of Fe₃O₄ and MoS₂ particles. To solve the governing differential equations, we used unsupervised heuristic based physics informed neural network (H-PINN) based fitness function<span><math><mo>.</mo></math></span> In this research, the weights and biases of neural network were optimized using a hybridization of heuristic algorithms to achieve high accuracy. The fitness values obtained from proposed approach ranging from<span><math><mspace></mspace><msup><mn>10</mn><mrow><mo>−</mo><mn>05</mn></mrow></msup></math></span> to<span><math><mspace></mspace><msup><mn>10</mn><mrow><mo>−</mo><mn>08</mn></mrow></msup></math></span>. The optimal results were then compared with numerical solutions obtained by using Runge-Kutta order-4 method through BVP4c tool as a reference solution, demonstrating the effectiveness of the unsupervised ANN method. The absolute error between the reference solution and proposed heuristic based physics informed neural networks approaches are ranging from<span><math><mspace></mspace><mn>2.36</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>04</mn></mrow></msup><mspace></mspace><mtext>to</mtext><mspace></mspace><mn>3.46</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>06</mn></mrow></msup></math></span>, <span><math><mn>2.77</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>05</mn></mrow></msup><mspace></mspace><mtext>to</mtext><mspace></mspace><mn>1.20</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>05</mn></mrow></msup></math></span> and<span><math><mspace></mspace><mn>1.10</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>06</mn></mrow></msup><mspace></mspace><mtext>to</mtext><mspace></mspace><mn>6.53</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>07</mn></mrow></msup></math></span>. Our findings demonstrate a strong agreement with the numerical approach, with the maximum discrepancy in the profiles of flow speed and energy profiles. Notably, we observed that an increase in the squeeze number and the Hartman number resulted in a reduction in the velocity profile.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108320"},"PeriodicalIF":6.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653667","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}

{"title":"Experimental study of R134a and its alternative mixture R450A flow boiling in a microchannel tube","authors":"Chao Yuan ,&nbsp;Shenghan Jin ,&nbsp;Hongqiang Li ,&nbsp;Zhongbin Liu ,&nbsp;Jinqing Peng ,&nbsp;Houpei Li","doi":"10.1016/j.icheatmasstransfer.2024.108319","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108319","url":null,"abstract":"<div><div>R450A has a low Global Warming Potential, which is considered a replacement for R134a. This study measures the pressure gradient and heat transfer coefficient of both R134a and R450A during boiling in a multiport microchannel tube. The mass fluxes change from 100 to 200 kg-m⁻² s⁻¹, heat fluxes from 2 to 4 kW-m⁻², and inlet saturation temperatures from 10 to 30 °C. Both refrigerants exhibit increased HTC with rising vapor quality, peaking at moderate vapor qualities (0.4 to 0.6). R450A shows higher increase in heat transfer coefficient at higher heat fluxes compared to R134a. Heat transfer coefficient enhances about 75 % when mass flux doubled for both refrigerants. The pressure gradient increases with vapor quality for both refrigerants, with R450A showing higher dP/dz. due to its lower vapor density and saturation pressure at the same saturation temperature. Higher mass flux results in higher and steeper pressure gradient. Lower saturation temperatures increase the pressure gradient due to lower vapor density. Kim and Mudawar model and Mishima and Hibiki model are both recommend for predicting pressure gradient. Liu and Winterton has low MAE and ME when comparing the predictions to measurements in this study, showing it is a relatively accurate model for predicting HTC for both R134a and R450A.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108319"},"PeriodicalIF":6.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653665","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}

{"title":"Experimental investigation on the influence of copper foam characteristics on pool boiling heat transfer","authors":"Yun Seok Choi ,&nbsp;Sung Jin Kim ,&nbsp;Il Woong Park ,&nbsp;Hyun Sun Park ,&nbsp;Yeon-Gun Lee","doi":"10.1016/j.icheatmasstransfer.2024.108318","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108318","url":null,"abstract":"<div><div>Advancements in technology have led to electronics with higher power densities, which strains the sustainability of these devices. In this context, using metal foams in pool boiling can provide solutions by enhancing heat transfer. The porous structure of metal foams affects the boiling parameters such as critical heat flux (CHF) and boiling heat transfer coefficient (BHTC). To study these effects, copper foams of varying thicknesses and PPI were used, and they were attached to smooth silicon surfaces to simulate chip cooling. This research focused on thin foams with 1 mm thickness, which had been sparsely explored in the previous studies. In the ten samples, the CHF increased by up to 85.8 %, and the BHTC increased by up to 141.1 %. Vapor bubble dynamics on copper foam surfaces, which were affected by the foam thickness and PPI, were analyzed. The experimental results show that copper foams significantly enhance pool boiling heat transfer. However, thicker foams increase the frequency of bubble trapping, causing localized overheating which leads to deterioration of heat transfer performance. There was also an optimal PPI value for each foam thickness, which is 40 PPI for the 1 mm thickness and 30 PPI for the 3 mm thickness.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108318"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653660","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}

{"title":"Performance prediction of flame-retardant clothing using correlations and artificial neural networks: Optimizing firefighter safety","authors":"Bhavna Rajput ,&nbsp;Sonika Sharma ,&nbsp;Bahni Ray ,&nbsp;Apurba Das ,&nbsp;Prabal Talukdar","doi":"10.1016/j.icheatmasstransfer.2024.108324","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108324","url":null,"abstract":"<div><div>Flame-Retardant Clothing serves as a protective shield for firefighters that safeguards them from exposure to heat, flames and other thermal hazards. To achieve an optimal design for the clothing, it is essential to simultaneously account for all the factors affecting the performance of the clothing. The present study employs data from a numerical model to explore heat and moisture transport through clothing subjected to flame exposure. Seventeen non-dimensionless parameters associated with the heat and moisture transport in flame-retardant clothing are obtained. A correlation is developed to link the dimensionless second-degree burn time with other non-dimensional parameters. This correlation provides a means to predict the thermal protective performance (TPP) of the clothing. Additionally, an Artificial Neural Network (ANN) method is employed to determine the TPP of the clothing. Multi-layer feedforward backpropagation networks are utilized to predict the TPP under specified exposure conditions. The findings indicate that both the correlations and the ANN approach adopted in the present study demonstrated promising results. However, the ANN model predictions show better agreement with model data in comparison to the results derived from the developed correlation. The maximum percentage error in the predicted non-dimensional second degree burn time using ANN is limited to 10 %.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108324"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653662","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}

{"title":"Cooling layout optimization for a turbine blade squealer tip with the application of oval holes","authors":"Jiajie Guo,&nbsp;Liming Song,&nbsp;Zhi Tao,&nbsp;Jun Li","doi":"10.1016/j.icheatmasstransfer.2024.108323","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108323","url":null,"abstract":"<div><div>For the purpose to enhance the cooling performance of the squealer tip under stage conditions, an automatic optimization framework was constructed to optimize the cooling holes on a squealer tip, including the utilization of oval-shaped holes. The analysis of the optimization results indicates that the configuration of the cooling holes with positive axial inclination and the reduction in the arrangement interval of holes that are assembled in the front cavity can effectively enhance the film attachment, resulting in augmented film coverage and cooling effectiveness. The coefficient of heat transfer in the region between and downstream the holes is observed to decrease in accordance with the film coverage. Meanwhile, the positive axial inclination guides the jets to accumulate towards the rear of the cavity, enhancing the blocking effect to leakage flow. The film attachment is further improved as the jets outflow along the long axis edge of oval holes, which exhibit low curvature. In general, the implementation of round hole optimization has led to an increase in cooling effectiveness by 54.85 % in comparison to the benchmark. Furthermore, the use of oval holes has resulted in a greater improvement of 67.65 %. The aerodynamic performance has remained uncompromised throughout these modifications.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108323"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653952","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}

{"title":"Parametric study for thermal uniformity analysis on vertical fin located in novel designed impacting-jet double-layer nested microchannel heat sinks verified by SLM 3D printing method","authors":"Han Shen ,&nbsp;Xinyue Lan ,&nbsp;Gongnan Xie ,&nbsp;Chi-Chuan Wang","doi":"10.1016/j.icheatmasstransfer.2024.108321","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108321","url":null,"abstract":"<div><div>The design of impacting-jet double-layer nested microchannel heat sinks (IJDN-MHS) has been proved to be an effective structure on heat dissipation improvement in electronic components. In order to achieve ideal substrate thermal uniformity for IJDN-MHS, the position research on vertical fin connecting inner/outer cooling circuit in IJDN-MHS has been studied numerically. Moreover, 3D printing test samples are made on the purpose of experimental verification using selective laser melting printing technology. As a result of the analysis, there is a strong correlation between the results of the numerical simulation and the experimental results. Through numerical simulation, it has been determined that the center fin position should be optimized for achieving the best thermal uniformity on the substrate. The model of distance between vertical fin connecting inner/outer cooling circuit and central point in IJDM-MHS equaling 0.27 mm (IJDN-MHS_0.27) has shown the optimal thermal symmetry on substrate. Further, with the streaming fins length increasing to 0.7 mm on the both sides of the vertical fin connecting inner/outer cooling circuit, thermal gradient at the bottom can be significantly controlled, and the peak temperature on substrate also drop to its most extreme limit based on the thermal uniformity on substrate.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108321"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653950","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}

{"title":"Water vapor and soot spatial characteristics retrieve of axisymmetric optically-thin laminar diffusion flame based on visible and near-infrared multi-spectral light field imaging","authors":"Tianjiao Li ,&nbsp;Yue Zhu ,&nbsp;Weiyi Zhang ,&nbsp;Bingkun Wu ,&nbsp;Dong Liu","doi":"10.1016/j.icheatmasstransfer.2024.108328","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108328","url":null,"abstract":"<div><div>The comprehension of the distribution of gaseous species and soot particles plays a pivotal role in investigating the combustion process of a flame. A highly effective method to accomplish this is by extracting visible and near-infrared emission information from flames. In this study, we present a novel near-infrared multi-spectral light field imaging model that enables the concurrent extraction of gas and soot property distributions within a flame. A synthetic test of ethylene diffusion flame is assessed using the proposed reconstruction method. The mole fraction of gaseous water, together with the flame temperature and soot volume fraction, are decoupled spectrally using near-infrared and visible wavelengths. The results demonstrate a reliably retrieved temperature range of 1400 K to 2050 K, accurately reconstructing the actual distributions of soot volume fraction and gaseous water mole fraction. Minor influences on the imaging results and property reconstruction are observed due to uncertainties arising from the reconstruction method, absorption function, reconstruction wavelength for H₂O mole fraction, and signal-to-noise ratio. This study serves as a theoretical guide for the future development of practical near-infrared multi-spectral light field imaging techniques for rapid and robust flame diagnostic purposes related to soot and gas properties.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108328"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653663","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}

{"title":"Experimental study on the dynamic evolution behavior and heat transfer of flame spread over continuously flowing diesel fuel","authors":"Sai Luo,&nbsp;JingBo Xu,&nbsp;Chen Wang,&nbsp;Jie Ji","doi":"10.1016/j.icheatmasstransfer.2024.108287","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108287","url":null,"abstract":"<div><div>Flame may spread over accidentally leaked liquid fuel, which is essentially related to multi-phase flows and heat transfer. This paper investigates the dynamic evolution behavior and the heat transfer mechanism of flame spread over stationary and flowing diesel fuel with various discharge flow rates. Results show that for flowing fuel cases, there is a considerable long-lasting unsteady flame spread stage, in which the subsurface flow velocity (<em>u</em>_<em>s</em>) and flame spread rate (<em>V</em>_<em>f</em>) increase as the spread proceeds. This is significantly different from flame spread over stationary fuel, in which <em>u</em>_<em>s</em> and <em>V</em>_<em>f</em> remain almost unchanged. Driving mechanism of the subsurface flow and variation of momentum balance is analyzed for the explanation. Besides, theoretical analysis is conducted to predict the acceleration, whose results agree with experimental data. Moreover, based on the momentum balance, it is found that <em>u</em>_<em>s</em> cannot be assumed to be linearly distributed along the fuel thickness, detailed velocity profiles are further clarified. In addition, dynamic variation of the heat transfer process is quantitatively revealed, and there is a transition of the dominant contribution to the heat needed for flame spread. Flame radiation plays a more significant role initially, as flame spreads, liquid convection gradually plays the dominant role.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108287"},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653661","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}

{"title":"Comparative experimental study on the thermal and hydraulic performances of capillary box heat exchanger and helical coil heat exchanger for surface water-source heat pump","authors":"Jinfu Zheng ,&nbsp;Changpeng Han ,&nbsp;Songtao Hu ,&nbsp;Qixiang Qin ,&nbsp;Jinda Wang ,&nbsp;Hui Zhu ,&nbsp;Shimin Liang","doi":"10.1016/j.icheatmasstransfer.2024.108331","DOIUrl":"10.1016/j.icheatmasstransfer.2024.108331","url":null,"abstract":"<div><div>The thermal and hydraulic performances of front-end heat exchangers significantly influence the energy efficiency of surface water-source heat pumps. To evaluate the performance of a capillary box heat exchanger (CBHE), a comparative study between the CBHE and a conventional helical coil heat exchanger (HCHE) was conducted under different tube velocities, heat transfer media, and temperatures. The comparison considered not only traditional metrics, such as the heat transfer coefficient, heat transfer efficiency, and pressure drop, but also the volume heat transfer coefficient and two thermal-hydraulic comprehensive performance parameters: the modified Colburn–Fanning factor ratio (<em>JF</em>_<em>K</em>) with larger-the-better characteristics and the electricity consumption to extracted or rejected heat quantity ratio (<em>EHR</em>) with smaller-the-better characteristics. The results indicated that the heat transfer coefficient, heat transfer efficiency, and volume heat transfer coefficient of the CBHE were 10.1 W/(m^2.°C)–25.58 W/(m^2.°C), 34 %–45 %, and 1140 W/(m^3.°C)–1416 W/(m^3.°C) larger than those of the HCHE, whereas its total pressure drop was only 15 %–21 % of that of the HCHE. Additionally, the <em>JF</em>_<em>K</em> and <em>EHR</em> of the CBHE were approximately three times and 11 %–16 %, respectively, those of the HCHE. This study serves as a reference for selecting and designing front-end heat exchangers.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"159 ","pages":"Article 108331"},"PeriodicalIF":6.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653951","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}