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 >

Ghinwa Al Mimar¹, Natrah Kamaruzaman^1,*, Kamil Talib Alkhateeb²

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1933-1956, 2025, DOI:10.32604/fhmt.2025.070118 - 31 December 2025

Abstract The pivotal role microchannels play in the thermal management of electronic components has, in recent decades, prompted extensive research into methods for enhancing their heat transfer performance. Among these methods, surface wettability modification was found to be highly effective owing to its significant influence on boiling dynamics and heat transfer mechanisms. In this study, we modified surface wettability using a nanocomposite coating composed of graphene nano plate (GNPs) and multi-walled carbon nanotubes (MWCNT) and then examined how the modification affected the transfer of boiling heat in microchannels. The resultant heat transfer coefficients for hydrophilic and… More >

Federico Sacchelli¹, Luca Cattani^1,2, Matteo Malavasi¹, Fabio Bozzoli^1,2,*, Corrado Sciancalepore¹

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1351-1364, 2025, DOI:10.32604/fhmt.2025.064154 - 31 October 2025

Abstract This study investigates the feasibility of a novel dual two-phase cooling system for thermal management in lithium-ion batteries used in electric vehicles (EVs). The proposed system aims to combine low-boiling dielectric fluid immersion cooling and pulsating heat pipes (PHPs), in order to leverage the advantages of both technologies for efficient heat dissipation in a completely passive configuration. Experimental evaluations conducted under different discharge conditions demonstrate that the system effectively maintains battery temperatures within the optimal range of 20–40°C, with enhanced temperature uniformity and stability. While the PHP exhibited minimal impact at low power, its role More >

Yifan Li^*, Congzhe Zhu, Rong Gao^*, Bin Yang

Energy Engineering, Vol.122, No.11, pp. 4523-4539, 2025, DOI:10.32604/ee.2025.068480 - 27 October 2025

Abstract The local overheating issue is a serious threat to the safe operation of data centers (DCs). The chip-level liquid cooling with pool boiling is expected to solve this problem. The effect of nano configuration and surface wettability on the boiling characteristics of copper surfaces is studied using molecular dynamics (MD) simulation. The argon is chosen as the coolant, and the wall temperature is 300 K. The main findings and innovations are as follows. (1) Compared to the smooth surface and fin surface, the cylindrical nano cavity obtains the superior boiling performance with earlier onset of… More > Graphic Abstract

Konstantin Busov^1,*, Nikolay Mazheiko¹, Leonid Plotnikov², Boris Zhilkin²

Frontiers in Heat and Mass Transfer, Vol.23, No.4, pp. 1203-1214, 2025, DOI:10.32604/fhmt.2025.067598 - 29 August 2025

Abstract Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out. The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters (temperature, pressure) along the saturation line in both the visible range and the infrared spectrum. The flow shapes corresponding to various modes of boiling-up have been identified. With thermal-imaging diagnostics, heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have More >

Ying Zhang^1,2, Chao Dang^1,2,*, Zhiqiang Zhang^1,2

Frontiers in Heat and Mass Transfer, Vol.23, No.4, pp. 1215-1242, 2025, DOI:10.32604/fhmt.2025.067373 - 29 August 2025

Abstract In this study, the flow boiling characteristics of R1234yf in parallel microchannels were experimentally investigated. The experiments were conducted with heat flux from 0 to 550 kW/m², mass flux of 434, 727, and 1015 kg/(m² s), saturation temperatures of 293, 298, and 303 K, and inlet sub-cooling of 5, 10, and 15 K. The analysis of the experimental results provides the following conclusions: a reduced mass flux and lower subcooling correspond to a diminished degree of superheat at the boiling inception wall; conversely, an elevated saturation temperature results in a reduced amount of superheat at the… More >

Zongyu Jie^1,2, Chao Dang^1,2,*, Qingliang Meng ^3,4

Frontiers in Heat and Mass Transfer, Vol.23, No.4, pp. 1053-1089, 2025, DOI:10.32604/fhmt.2025.066792 - 29 August 2025

Abstract With the increasing miniaturization of systems and surging demand for power density, accurate prediction and control of two-phase flow pressure drop have become a core challenge restricting the performance of microchannel heat exchangers. Pressure drop, a critical hydraulic characteristic, serves as both a natural constraint for cooling systems and determines the power required to pump the working fluid through microchannels. This paper reviews the characteristics, prediction models, and optimization measures of two-phase flow pressure drop for low-boiling-point working fluids in microchannels. It systematically analyzes key influencing factors such as fluid physical properties, operating conditions, channel… More >

Hao Tang^1,2,3, Jianchang Yang^1,2,3, Yunxin Zhou^1,2,3, Jianxin Xu^1,2,3,*, Hua Wang^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1571-1600, 2025, DOI:10.32604/fdmp.2025.063741 - 31 July 2025

Abstract This research explores the characteristics of boiling in inclined pipes, a domain of great importance in engineering. Employing an experimental visualization technique, the boiling dynamics of deionized water are examined at varying inclination angles, paying special attention to the emerging flow patterns. The findings demonstrate that the inclination angle significantly impacts flow pattern transitions within the 0° to 90° range. As the heat flux rises, bubbles form in the liquid. The liquid’s inertia extends the bubble-wall contact time, thereby delaying the onset of bulk bubble flow. Beyond a 90° inclination, however, the patterning behavior is… More > Graphic Abstract

Liaofei Yin^1,*, Kexin Zhang¹, Tianjun Qin¹, Wenhao Ma¹, Yi Ding¹, Yawei Xu^2,*

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 751-764, 2025, DOI:10.32604/fhmt.2025.067385 - 30 June 2025

Abstract Flow boiling in open microchannels offers highly efficient heat transfer performance and has attracted increasing attention in the fields of heat transfer and thermal management of electronic devices in recent years. However, the continuous rise in power density of electronic components imposes more stringent requirements on the heat transfer capability of microchannel flow boiling. HFE-7100, a dielectric coolant with favorable thermophysical properties, has become a focal point of research for enhancing flow boiling performance in open microchannels. The flow boiling heat transfer performance of HFE-7100 was investigated in this study by fabricating micro-nano composite structures… More >

Alexey Melkikh^1,2, Sergey Rutin², Dmitrii V. Antonov³, Pavel Skripov^2,*

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 721-737, 2025, DOI:10.32604/fhmt.2025.066528 - 30 June 2025

Abstract The article considers a relaxation of the water/polypropylene glycol-425 solution with a lower critical solution temperature (LCST) following its pulsed superheating concerning liquid-liquid and liquid-vapor equilibrium lines, as well as the liquid-liquid spinodal. Superheating was performed using the pulsed heat generation method in a micro-sized wire probe. The main heating mode was the constant (over the pulse length) power mode. Characteristic heating rates ranged from 0.05 × 10⁵ to 2 × 10⁵ K/s, while the degree of superheating concerning the spinodal was up to 200 K. The temperature of spontaneous boiling-up and the amplitude of the… More > Graphic Abstract