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 >

Amina Mahreen¹, Fateh Mebarek-Oudina^2,3,4,*, Amna Ashfaq¹, Jawad Raza¹, Sami Ullah Khan⁵, Hanumesh Vaidya⁶

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.11, pp. 2829-2853, 2025, DOI:10.32604/fdmp.2025.072492 - 01 December 2025

Abstract Understanding the complex interaction between heat and mass transfer in non-Newtonian microflows is essential for the development and optimization of efficient microfluidic and thermal management systems. This study investigates the magnetohydrodynamic (MHD) thermosolutal convection of a Casson fluid within an inclined, porous microchannel subjected to convective boundary conditions. The nonlinear, coupled equations governing momentum, energy, and species transport are solved numerically using the MATLAB bvp4c solver, ensuring high numerical accuracy and stability. To identify the dominant parameters influencing flow behavior and to optimize transport performance, a comprehensive hybrid optimization framework—combining a modified Taguchi design, Grey… 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 >

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 >

Shervin Fateh Khanshir¹, Saeed Dinarvand^2,*, Ramtin Fateh Khanshir³

Frontiers in Heat and Mass Transfer, Vol.23, No.2, pp. 663-684, 2025, DOI:10.32604/fhmt.2025.060559 - 25 April 2025

Abstract This article aims to model and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose (CMC) nanofluid within a convergent-divergent shaped microchannel (Two-dimensional). The base fluid, water + CMC (0.5%), is mixed with CuO and Al₂O₃ nanoparticles at volume fractions of 0.5% and 1.5%, respectively. The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid. Three types of microchannels including straight, divergent, and convergent are considered, all having the same length and identical inlet cross-sectional area. Using ANSYS FLUENT software, Navier-Stokes equations… More > Graphic Abstract

Heng Zhao¹, Honghua Ma², Hui Liu¹, Xiang Yan¹, Huaqing Yu¹, Yongjun Xiao¹, Xiao Xiao^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.1, pp. 87-105, 2025, DOI:10.32604/fdmp.2024.056577 - 24 January 2025

Abstract The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks (MCHS) subjected to a uniform heat flux is investigated by means of numerical simulations. Various geometrical configurations are examined, particularly, the combinations of rectangular solid and perforated blocks, used to create a disturbance in the flow. The analysis focuses on several key aspects and related metrics, including the temperature distribution, the mean Fanning friction factor, the pressure drop, the Nusselt number, and the overall heat transfer coefficient across a range of Reynolds numbers (80–870). It is shown that the introduction of such More >

Long Huang^1,2,3,*, Junjia Zou³, Baoqing Liu¹, Zhijiang Jin^1,2, Jinyuan Qian¹

Frontiers in Heat and Mass Transfer, Vol.22, No.6, pp. 1613-1643, 2024, DOI:10.32604/fhmt.2024.058231 - 19 December 2024

Abstract This study explores the effectiveness of machine learning models in predicting the air-side performance of microchannel heat exchangers. The data were generated by experimentally validated Computational Fluid Dynamics (CFD) simulations of air-to-water microchannel heat exchangers. A distinctive aspect of this research is the comparative analysis of four diverse machine learning algorithms: Artificial Neural Networks (ANN), Support Vector Machines (SVM), Random Forest (RF), and Gaussian Process Regression (GPR). These models are adeptly applied to predict air-side heat transfer performance with high precision, with ANN and GPR exhibiting notably superior accuracy. Additionally, this research further delves into… More >

Ali M. H. Al-Obaidy^*, Ekhlas M. Fayyadh, Amer M. Al-Dabagh

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1421-1442, 2024, DOI:10.32604/fhmt.2024.055063 - 30 October 2024

Abstract High heat dissipation is required for miniaturization and increasing the power of electronic systems. Pool boiling is a promising option for achieving efficient heat dissipation at low wall superheat without the need for moving parts. Many studies have focused on improving heat transfer efficiency during boiling by modifying the surface of the heating element. This paper presents an experimental investigation on improving pool boiling heat transfer using an open microchannel. The primary goal of this work is to investigate the impact of the channel geometry characteristics on boiling heat transfer. Initially, rectangular microchannels were prepared… More > Graphic Abstract