Mussad Mohammed Al-Zahrani^*, Taher Maatallah

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1883-1905, 2025, DOI:10.32604/fhmt.2025.074656 - 31 December 2025

Abstract Conventional concentrator photovoltaics (CPV) face a persistent trade-off between high efficiency and high cost, driven by expensive multi-junction solar cells and complex active cooling systems. This study presents a computational investigation of a novel Multi-Focal Pyramidal Array (MFPA)-based CPV system designed to overcome this limitation. The MFPA architecture employs a geometrically optimized pyramidal concentrator to distribute concentrated sunlight onto strategically placed, low-cost monocrystalline silicon cells, enabling high efficiency energy capture while passively managing thermal loads. Coupled optical thermal electrical simulations in COMSOL Multiphysics demonstrate a geometric concentration ratio of 120×, with system temperatures maintained below More >

Guofeng Han, Chenxi Luo, Xin Liu, Yuanyuan Li, Yuling Cheng, Shuai Huang, Dan Huang^*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1981-1999, 2025, DOI:10.32604/fhmt.2025.074593 - 31 December 2025

Abstract Bananas are highly perishable after harvest, and processing them into dried products is a crucial approach to reducing losses and adding their economic values. To address the inefficiency and prolonged duration of traditional hot air drying (HAD) and the quality inconsistency associated with single infrared drying (IRD), this study proposed a novel hot air-infrared combined drying (HAD-IRD) strategy. The effects of HAD, IRD, and HAD-IRD on the drying kinetics, color, rehydration capacity, moisture diffusion mechanism, and sensory quality of banana slices were systematically investigated. The parameters of the combined drying process were optimized using an L₉(3³)… More >

Xiaoyan Zhuo¹, Yukun Ji¹, Yatao Ren^1,*, Xuehui Wang², Hong Qi¹

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1701-1720, 2025, DOI:10.32604/fhmt.2025.074045 - 31 December 2025

Abstract Flow and heat transfer characteristics during droplet impact on hot walls are pivotal for elucidating the mechanisms of spray cooling and exploring pathways for heat transfer enhancement. When the wall temperature exceeds the Leidenfrost point, a vapor film forms between the droplet and the wall, rendering the heat transfer process highly complex. Furthermore, for droplet impact on curved walls, the presence of curvature introduces additional factors that modify the spreading behavior of the droplet and necessitate in-depth analysis. Therefore, this work investigates the flow and heat transfer dynamics of droplet impact on hot planes and… More >

Dong Hu^1,2, Lingxing Hu³, Facheng Qiu^3,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1865-1882, 2025, DOI:10.32604/fhmt.2025.073409 - 31 December 2025

Abstract With the acceleration of industrialization and urbanization, ammonia nitrogen pollution in water bodies has become increasingly severe, making the development of efficient and low-consumption wastewater treatment technologies highly significant. This study employs three-dimensional computational fluid dynamics (CFD) to investigate the cavitation mechanisms and flow field characteristics in a novel jet impingement-negative pressure ammonia removal reactor. The simulation, validated by experimental pressure data with a high degree of consistency, utilizes the Mixture model, the Realizable k-ε turbulence model, and the Schnerr-Sauer cavitation model. The results demonstrate that the flow velocity undergoes a substantial acceleration within the… More > Graphic Abstract

Shuo Wang^1,2,*, Huiming Wang^1,2, Ying Zhang^1,2, Zhiqiang Zhang^1,3, Li Jia^1,2

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1721-1740, 2025, DOI:10.32604/fhmt.2025.073226 - 31 December 2025

Abstract This experimental investigation was conducted on the flow boiling performance of refrigerant R134a in two types of parallel microchannels: sintered porous microchannels (PP-MCs) and smooth parallel microchannels (SP-MCs). The tests were performed under controlled conditions including an inlet subcooling of 5 ± 0.2°C, saturation temperature of 33°C, mass fluxes of 346 and 485 kg/m²·s, and a range of heat fluxes. Key findings reveal that the sintered porous microstructure significantly enhances bubble nucleation, reducing the wall superheat required for the onset of nucleate boiling (ONB) to only 0.13°C compared to 2.2°C in smooth channels. The porous structure… More >

Liangjian Lei^1,2, Yihang Lu^1,2,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2109-2126, 2025, DOI:10.32604/fhmt.2025.072643 - 31 December 2025

Abstract Internal thermal mass, such as furniture and partitions, plays a crucial role in enhancing building energy efficiency and indoor thermal comfort by passively regulating temperature fluctuations. However, the irregular geometry of these elements poses a significant challenge for accurate modeling in building energy simulations. This study addresses this gap by developing a rigorous analytical model that idealizes internal thermal mass as a sphere, thereby capturing multi-directional heat conduction effects that are neglected in simpler one-dimensional slab models. The transient heat conduction within the sphere is solved analytically using Duhamel’s theorem for three representative indoor air… More >

Jinyou Qiu^1,2, Jiale Liu^1,2, Yubing Li^1,2,*, Shaogeng Zhong³, Guilong Dai^1,2, Wenhua Liu⁴

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2025-2049, 2025, DOI:10.32604/fhmt.2025.072260 - 31 December 2025

Abstract The growing demand for energy-saving and renewable heating solutions has made photovoltaic/thermal (PV/T) heat pump systems a promising technology. However, their thermal and electrical performance, as well as the overall utilization of solar energy, strongly depend on capacity configuration and operating parameters. To address this issue, this study proposes a PV/T heat pump system featuring a novel rhombic flow channel structure that functions as the collector-evaporator. An experimental test bench was established to evaluate system performance, and a one-dimensional numerical model was developed to investigate the effects of environmental and operating parameters. The simulation results… More > Graphic Abstract

Shengzhong Zhao¹, Daiyan Chen¹, Han Zhang^1,2,*, Junhao Yu¹, Lin Xu¹, Zhaoyi Zhuang¹, Fei Wang^1,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1907-1932, 2025, DOI:10.32604/fhmt.2025.071910 - 31 December 2025

Abstract A sealed portal could significantly alter the flame shape and smoke flow characteristics in inclined tunnel fires. In inclined tunnels, two typical sealing conditions could be defined, namely the upper portal sealed and the lower portal sealed. In this study, the effects of tunnel slope on flame shape, flame length, along with smoke mass flow rate and induced velocity at the tunnel portal, are numerically investigated. The results show that, in all scenarios, flames initially rise vertically but tilt toward the sealed portal during the quasi-steady stage, with the largest tilt angle observed in tunnels… More >

Lei Wang¹, Hongyang Zhou², Xiaofan Liu³, Junkun Mu², Jinpeng Bi², Youkang Jin², Juan Ge², Yuexia Lv^2,4,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1811-1832, 2025, DOI:10.32604/fhmt.2025.071222 - 31 December 2025

Abstract Membrane gas absorption and solar-assisted absorbent regeneration offer a sustainable approach to reduce the energy penalty of post-combustion CO₂ capture. This study introduces a novel system integrating solar thermal energy with membrane gas absorption to capture CO₂ from a 580 MWe pulverized coal power plant. The environmental impacts across six scenarios at varying solar fractions are evaluated via life cycle assessment. Results show a 7.61%–13.04% reduction in global warming potential compared to a steam-driven CO₂ capture system. Electricity and steam consumption dominate the operational phase, contributing 15%–64% and 18%–61% to environmental impacts in non-TES scenarios, respectively. While More >

Yang Liu¹, Biao Chen¹, Xin Liu², Chenxi Luo², Shihui Xiao^2,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 2127-2146, 2025, DOI:10.32604/fhmt.2025.070973 - 31 December 2025

Abstract This study evaluated corn kernel drying performance and quality changes using hot air drying (HAD) and infrared drying (ID) across temperatures ranging from 55°C to 80°C. Optimal drying parameters were determined by using the entropy weight method, with drying time, specific energy consumption, damage rate, fatty acids, starch, polyphenols, and flavonoids as indicators. Results demonstrated that ID significantly outperformed HAD, achieving drying times up to 20% shorter and reducing specific energy consumption and kernel damage by up to 79.3% and 66.7%, respectively, while also better preserving quality attributes. Both methods exhibited drying profiles characterized by More >