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Yangyiming Rong¹, Weitao Su¹, Shuai Wang², Bowen Du¹, Jianjian Wei², Shaozhi Zhang^2,*
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.052415
（This article belongs to the Special Issue: Computational and Numerical Advances in Heat Transfer: Models and Methods II)
Abstract Finned-tube heat exchanger (FTHE) is often used as an evaporator in commercial products of separated heat pipe (SHP). The working conditions of FTHE in gravity-assisted SHP are significantly different from those working in refrigerators and air conditioners. Although FTHE is widely used in commercial products of SHP, previous research on its characteristics is very limited. In this paper, a mathematical model for a SHP with FTHE as the evaporator and plate heat exchanger as the condenser is established and verified with experiments. Parametric analyses are carried out to investigate the influences of evaporator design parameters:… More >

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Haowei Hu^1,2,*, Xinnuo Chen¹, Qi Wang¹, Qin Li³, Dong Niu⁴, Mu Du^5,*
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.054218
Abstract The self-driven behavior of droplets on a functionalized surface, coupled with wetting gradient and wedge patterns, is systematically investigated using molecular dynamics (MD) simulations. The effects of key factors, including wedge angle, wettability, and wetting gradient, on the droplet self-driving effect is revealed from the nanoscale. Results indicate that the maximum velocity of droplets on hydrophobic wedge-shaped surfaces increases with the wedge angle, accompanied by a rapid attenuation of driving force; however, the average velocity decreases with the increased wedge angle. Conversely, droplet movement on hydrophilic wedge-shaped surfaces follows the opposite trend, particularly in terms… More >

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Bo Zhang¹, Yunxie Huang², Peilin Cui², Zhiguo Wang¹, Duo Ding¹, Zhenhai Pan³, Zhenyu Liu^2,*
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.053592
（This article belongs to the Special Issue: Fluid Flow, Heat and Mass Transfer within Novel Cooling Structures)
Abstract The high surface area of porous media enhances its efficacy for evaporative cooling, however, the evaporation of pure substances often encounters issues including local overheating and unstable heat transfer. To address these challenges, a volume of fluid (VOF) model integrated with a species transport model was developed to predict the evaporation processes of ternary mixtures (water, glycerol, and 1,2-propylene glycol) in porous ceramics in this study. It reveals that the synergistic effects of thermal conduction and convective heat transfer significantly influence the mixtures evaporation, causing the fluctuations in evaporation rates. The obtained result shows a More >

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Zakaria Triki¹, Ahmed Selloum¹, Younes Chiba¹, Hichem Tahraoui^1,2, Dorsaf Mansour³, Abdeltif Amrane^4,*, Meriem Zamouche⁵, Mohammed Kebir⁶, Jie Zhang⁷
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.052223
（This article belongs to the Special Issue: Innovative Heat Transfer Fluids for Enhanced Energy Sustainability in Thermal Systems)
Abstract Refrigeration plays a significant role across various aspects of human life and consumes substantial amounts of electrical energy. The rapid advancement of green cooling technology presents numerous solar-powered refrigeration systems as viable alternatives to traditional refrigeration equipment. Exergy analysis is a key in identifying actual thermodynamic losses and improving the environmental and economic efficiency of refrigeration systems. In this study exergy analyze has been conducted for a solar-powered vapor compression refrigeration (SP-VCR) system in the region of Ghardaïa (Southern Algeria) utilizing R1234ze(E) fluid as an eco-friendly substitute for R134a refrigerant. A MATLAB-based numerical model was… More >

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Amal El Berry, Marwa M. Ibrahim^*, A. A. Elfeky, Mohamed F. Nasr
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.050684
Abstract A photovoltaic (PV) inverter is a vital component of a photovoltaic (PV) solar system. Photovoltaic (PV) inverter failure can mean a solar system that is no longer functioning. When electronic devices such as photovoltaic (PV) inverter devices are subjected to vapor condensation, a risk could occur. Given the amount of moisture in the air, saturation occurs when the temperature drops to the dew point, and condensation may form on surfaces. Numerical simulation with “COMSOL Software” is important for obtaining knowledge relevant to preventing condensation by using two steps. At first, the assumption was that the… More >

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Matiewos Mekonen Abera^1,2,*, Venkata Ramayya Ancha¹, Balewgize Amare¹, L. Syam Sundar³, Kotturu V. V. Chandra Mouli⁴, Sambasivam Sangaraju⁵
Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2024.049525
（This article belongs to the Special Issue: Entropy Generation and Exergy Analysis of Thermal Devices)
Abstract This study is focused on the simulation and optimization of packed-bed solar thermal energy storage by using sand as a storage material and hot-water is used as a heat transfer fluid and storage as well. The analysis has been done by using the COMSOL multi-physics software and used to compute an optimization charging time of the storage. Parameters that control this optimization are storage height, storage diameter, heat transfer fluid flow rate, and sand bed particle size. The result of COMSOL multi-physics optimized thermal storage has been validated with Taguchi method. Accordingly, the optimized parameters… More >

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