Heat Transfer Research最新文献

Numerical analysis of thermoacoustic heat pump driving by prime mover 原动机驱动热声热泵的数值分析

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-09-01 DOI: 10.1615/heattransres.2024053033

Dongwei Zhang, Jian Guan, Zhuantao He, Chao Shen, Hongxin Li, Songzhen Tang, Lin Wang, Yonggang Lei

引用次数: 0

Evaluation of the performance of using R410A and R463A in a vapor compression refrigeration system: Energetic-exergetic analysis and Environmental Impact Index (EII) assessmen 评估在蒸汽压缩制冷系统中使用 R410A 和 R463A 的性能：能效分析和环境影响指数（EII）评估

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-09-01 DOI: 10.1615/heattransres.2024054447

Ragıp Yıldırım, Kazım Kumaş, Ali Akyüz, Azim Doğuş Tuncer

{"title":"Evaluation of the performance of using R410A and R463A in a vapor compression refrigeration system: Energetic-exergetic analysis and Environmental Impact Index (EII) assessmen","authors":"Ragıp Yıldırım, Kazım Kumaş, Ali Akyüz, Azim Doğuş Tuncer","doi":"10.1615/heattransres.2024054447","DOIUrl":"https://doi.org/10.1615/heattransres.2024054447","url":null,"abstract":"A thorough evaluation of the new generation of refrigerants before their application in vapor compression cooling cycles enables prudent action to be taken. This study presents a comparative analysis between R463A and R410A in vapor compression refrigeration cycles. R463A exhibits notable advantages: it demonstrates higher mass flow rates owing to its elevated density at -25°C evaporator temperature, resulting in superior cooling capacities at 40°C and 45°C. However, this superiority comes at the cost of higher energy demand than R410A, which is evident in its increased energy consumption at these temperatures. Despite its enhanced cooling capacity, R463A displays slightly lower COP attributed to its higher compressor energy utilization. Moreover, both refrigerants exhibit increased exergy destruction with rising temperatures, consequently impacting exergy efficiency, which is slightly lower for R463A due to its elevated exergy destruction rates. Environmental impact analyses also highlight R463A's consistently higher environmental index than R410A across varied temperatures. This comprehensive evaluation contributes insights into R463A's performance as an alternative refrigerant to R410A in vapor compression systems.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"75 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

An investigation over the influence of a radiant thermal mat’s dimensions on its local and average convective and radiative heat transfer characteristics 研究辐射热垫的尺寸对其局部和平均对流及辐射传热特性的影响

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-08-01 DOI: 10.1615/heattransres.2024052874

Ozgen Acikgoz

{"title":"An investigation over the influence of a radiant thermal mat’s dimensions on its local and average convective and radiative heat transfer characteristics","authors":"Ozgen Acikgoz","doi":"10.1615/heattransres.2024052874","DOIUrl":"https://doi.org/10.1615/heattransres.2024052874","url":null,"abstract":"For living spaces, radiant thermal mats are seen to be a good substitute for traditional heating systems. These devices, which are often powered by electricity, are installed on the floors, walls, and ceilings of rooms. The heat generated by the mat's absolute temperature causes direct and focused heating. The natural convection heat transfer properties of radiant heating and cooling systems have been well studied, while the properties of radiant mats placed on surfaces have received relatively less attention. Mats of square and rectangular dimensions (axb=0.5 m x 0.5 m, 1 m x 1 m, 1.2 m x 1.2 m, 1.4 m x 1.4 m, 1 m x 1.2 m, 1 m x 1.4 m, and 1 m x 1.6 m) are installed on the walls of an enclosure with floor dimensions (LxL= 4 m x 4 m) and a height of H= 3 m in order to address this gap in the literature. Average convective, radiative, and overall heat transfer characteristics—which are important for building energy simulation programs—are found and correlated for different mat dimensions using the surface-to-surface (S2S) radiation model and the k-ε RNG turbulence model in the numerical program, with error ranges of ±5%, ±5%, and ±15%, respectively.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"25 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Employing thin planar electrodes to expand the ionic wind flow coverage area and achieve enhanced heat dissipation 采用薄平面电极，扩大离子风流覆盖面积，增强散热效果

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-08-01 DOI: 10.1615/heattransres.2024053614

Yu-qing Ji, Jing Wang, Shi-chun Xiao, Wen-jie Shen, An Li

{"title":"Employing thin planar electrodes to expand the ionic wind flow coverage area and achieve enhanced heat dissipation","authors":"Yu-qing Ji, Jing Wang, Shi-chun Xiao, Wen-jie Shen, An Li","doi":"10.1615/heattransres.2024053614","DOIUrl":"https://doi.org/10.1615/heattransres.2024053614","url":null,"abstract":"The suboptimal photoelectric conversion efficiency of light-emitting diodes (LEDs) leads to increased temperature. There is a growing interest in using micro-structure ionic wind pumps to regulate the chip temperature. But the ionic wind flow and thermal transfer characteristics of thin-plate electrode pumps used for cooling LED chips is unclear. This study proposes ionic wind pumps equipped with wedged and zigzag-emitters to effectively manage the heat generated by high-power LED chips. Experimental investigations were conducted to analyze the electrohydrodynamic characteristics of pumps with different emitter types. A two-dimensional model with a wedged-electrode and a three-dimensional model with a zigzag-electrode were developed for flow distribution analysis and energy efficiency comparison. The cooling capacity of pumps with different configurations was examined. The results show that the pump equipped with a zigzag-electrode exhibits improved stability in corona discharge and approximately 1.53 times higher energy efficiency compared to the pump with a wedged-electrode. Moreover, the pump with the zigzag-electrode covers a larger area, generating a higher intensity of ionic wind. The angle between the emitter and the ground electrode significantly affects the characteristics of the characteristics of the ionic wind flow. The optimal angle is 70° for pumps with wedged-emitters and 30° for those with zigzag emitters. Both pumps can produce a steady wall jet at their optimal angle, causing significant disruption in the surrounding area. The pump with zigzag-electrode exhibits superior cooling performance and is more effective with low power consumption.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"68 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

COOLING EFFECT OF DIFFERENT TYPES OF MATERIALS IN AN AVIONICS SYSTEM 航空电子系统中不同类型材料的冷却效果

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-08-01 DOI: 10.1615/heattransres.2024053465

Rasim BEHÇET, Melih ATEŞ, Yahya ÖZ

{"title":"COOLING EFFECT OF DIFFERENT TYPES OF MATERIALS IN AN AVIONICS SYSTEM","authors":"Rasim BEHÇET, Melih ATEŞ, Yahya ÖZ","doi":"10.1615/heattransres.2024053465","DOIUrl":"https://doi.org/10.1615/heattransres.2024053465","url":null,"abstract":"Equipment used in the aviation industry heats up over time depending on working conditions. It is possible to preserve the properties of equipment affected by heat by either cooling the system and returning it to initial conditions or by producing the system from materials that are not affected by heat much. One of the areas where nanocomposite materials will be used is avionic systems in the aviation and space industry. These systems are structures in which elements such as sensors, cabling and processors, which form the basis of the electronic structure of flight, are brought together in very small volumes. It is important that the material used in these structures is light and has high strength and has electromagnetic properties selected accordingly. In this study, the thermal analysis of Vapor Grown Carbon Fiber (VGCF) nanocomposite materials produced by adding them to the epoxy matrix in terms of the thermal performance of avionic boxes was carried out by comparing them with the thermal properties of the aluminum material. As a result of the findings obtained from thermal analysis studies carried out in four stages for this purpose; It was observed that by using VGCF composite instead of aluminum material, approximately 23% improvement in temperature output and 17% improvement in thermal load was achieved. Thus, it is anticipated that energy efficiency will be increased with the use of lightweight and high-strength nanocomposite materials, which is considered one of the most important goals of the aviation industry.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"196 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Comparative experimental investigation on viscosity and stability of W/EG based non-Newtonian hybrid nanofluids for the heat transfer applications 基于 W/EG 的非牛顿混合纳米流体在传热应用中的粘度和稳定性对比实验研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-08-01 DOI: 10.1615/heattransres.2024053694

Ayush Painuly, Niraj Mishra, Prabhakar Zainith, Gaurav Joshi

{"title":"Comparative experimental investigation on viscosity and stability of W/EG based non-Newtonian hybrid nanofluids for the heat transfer applications","authors":"Ayush Painuly, Niraj Mishra, Prabhakar Zainith, Gaurav Joshi","doi":"10.1615/heattransres.2024053694","DOIUrl":"https://doi.org/10.1615/heattransres.2024053694","url":null,"abstract":"This study investigates the stability and rheological properties of water-ethylene glycol (W/EG) based non-Newtonian hybrid nanofluids incorporating SiC, Al2O3 and MWCNT nanoparticles. A two-step method was employed to prepare the hybrid nanofluids, using X-ray diffraction (XRD) and scanning electron microscopy (SEM) for the characterization of the nanoparticles. Stability assessment showed that Al2O3-MWCNT hybrid nanofluids are more optically stable than SiC-MWCNT as W/EG based Al2O3-MWCNT hybrid nanofluids took longer to sediment. Al2O3-MWCNT hybrid nanofluids exhibited superior stability in visual tests over a period of 19–21 days while SiC-MWCNT nanofluid took 12-14 days to sediment. Rheological analysis showed that increasing particle concentration increased the viscosity by 3.56 and 3.98 times for SiC-MWCNT and Al2O3-MWCNT hybrid nanofluids, respectively, compared to the base fluid. In contrast, increasing the temperature from 25 °C to 55 °C decreased the shear stress by 72.8% and 64.8% for SiC-MWCNT and Al2O3-MWCNT hybrid nanofluids respectively. Furthermore, the viscosity versus shear rate trends indicated a pseudoplastic or shear-thinning nature for both hybrid nanofluids with particle volume fraction above or equal to 0.1%.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"77 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142193100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 step forward on the network method for radiation heat transfer analysis in enclosures 围护结构辐射传热分析网络法向前迈进了一步

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-07-01 DOI: 10.1615/heattransres.2024053249

Vitor Costa

{"title":"A step forward on the network method for radiation heat transfer analysis in enclosures","authors":"Vitor Costa","doi":"10.1615/heattransres.2024053249","DOIUrl":"https://doi.org/10.1615/heattransres.2024053249","url":null,"abstract":"It is proposed an approach of the network method for radiation in enclosures that expresses radiosities and irradiations as functions of the blackbody emissive powers and of the radiation fluxes entering the enclosure through its partially transparent walls. These results are used to express the radiation heat flow exchanged between two surfaces and the net radiation heat flux leaving each of the enclosure’s surfaces as depending on these true driving forces for radiation heat transfer. This reduces the problem to its essential, as these are the true driving forces for the radiation heat transfer. Net radiation heat fluxes leaving each of the enclosure’s surfaces form an equations’ system from which are evaluated the relevant radiation heat transfer parameters for each surface. Proposed approach is based on elementary matrices operations, the main attention being dedicated to the problem setting and leaving the (just essential) calculations to the calculator or to the computer. It is introduced for enclosures with all opaque walls and illustrated for one example, and then extended to enclosures with partially transparent walls. Proposed simplifying and unifying approach is relevant not only for radiation heat transfer analysis and calculations, but also for pedagogical purposes, retaining attention on the essential of the radiation heat transfer problem formulation, setting aside intermediate/auxiliary variables calculations that are usually aversive, fastidious, distractive and prone to errors.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"61 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141608463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

PHASE CHANGE MATERIALS (PCMS) FOR BUILDINGS AND AUTOMOTIVE APPLICATIONS: A REVIEW STUDY 建筑和汽车应用中的相变材料 (PCMS)：回顾研究

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-07-01 DOI: 10.1615/heattransres.2024053911

Mahdi Tabatabaei Malazi, Faraz Afshari, Kenan Kaya

引用次数: 0

Experimental evaluation of HFC/HFO binary mixtures in a small-scale water-to-water heat pump system 小型水-水热泵系统中氢氟碳化合物/氢氟烯烃二元混合物的实验评估

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-07-01 DOI: 10.1615/heattransres.2024054108

Ragıp Yıldırım, Abdullah Yıldız, Azim Doğuş Tuncer

{"title":"Experimental evaluation of HFC/HFO binary mixtures in a small-scale water-to-water heat pump system","authors":"Ragıp Yıldırım, Abdullah Yıldız, Azim Doğuş Tuncer","doi":"10.1615/heattransres.2024054108","DOIUrl":"https://doi.org/10.1615/heattransres.2024054108","url":null,"abstract":"In this study, two different hydrochlorofluorocarbon (HFC) / Hydrofluoroolefin (HFO) binary blends (R134a/R1234yf (75/25) and R134a/R1234yf (25/75)) are studied experimentally. Energetic, exergetic and LCCP (life cycle climate performance) evaluations of the heat pump for HFC/HFO binary blends were carried out. In the literature, no studies are available on the use of HFC/HFO in heat pumps or cooling systems at these blend ratios. This study differs from previous studies on HFC/HFO binary mixtures. Therefore, it will contribute to the literature on binary HFC/HFO blends with lower global warming potential (GWP). HFC/HFO binary blends for different temperature of evaporator (-10 °C, -5 °C, 0 °C) and fixed temperature of condenser (35 °C) were studied. The performance of R134a/R1234yf (75/25) refrigerant blend is superior to R134a/R1234yf (25/75) refrigerant blend based on the 1st and 2nd laws of thermodynamics. Although the GWP of R134a/R1234yf (75/25) is higher than that of R134a/R1234yf (25/75), R134a/R1234yf (75/25) has a relatively smaller total LCCP than R134a/R1234yf (25/75). Low GWP is not the only criterion for selecting a refrigerant. Energy and exergy are also important. Because an important part of the overall system emissions of the heat pump is seen to be caused by the consumption of energy.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":"30 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141532233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Heat transfer enhancement behind an obstacle in a channel flow undergoing transition to turbulence 过渡到湍流的通道流中障碍物后的传热增强

IF 1.7 4区工程技术

Heat Transfer Research Pub Date : 2024-07-01 DOI: 10.1615/heattransres.2024054158

Alexander Mazo, Evgeniy Kalinin, Valery Molochnikov, Dmitry Okhotnikov, Anton Paereliy, Olga Dushina

引用次数: 0