Chao Gui^1,2, Wanying Chang³, Yaping Liu^1,*, Leren Tao³, Daoming Shen¹, Mengyi Ge¹

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1621-1637, 2025, DOI:10.32604/fhmt.2025.072268 - 31 October 2025

Abstract Freeze-drying of structurally heterogeneous biomaterials such as porcine aorta presents considerable modeling challenges due to their inherent multilayer composition and moving sublimation interfaces. Conventional models often overlook structural anisotropy and dynamic boundary progression, while experimental determination of key parameters under cryogenic conditions remains difficult. To address these, this study develops a heat and mass transfer model incorporating a dynamic node strategy for the sublimation interface, which effectively handles continuous computational domain deformation. Additionally, specialized fixed nodes were incorporated to adapt to the multilayer structure and its spatially varying thermophysical properties. A novel non-contact gravimetric system More > Graphic Abstract

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 >

Xingjie Ren^1,2,#,*, Jianrong Zhang^3,4,#, Qingfeng Tang³, Heng Zhang³, Yaling Zhang^3,4,*

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 881-897, 2025, DOI:10.32604/fhmt.2025.066302 - 30 June 2025

Abstract This paper investigates interfacial heat transfer characteristics in a multi-layer structure under ultra-high heat flux conditions, focusing on thermal contact resistance (TCR) between adjacent layers. A three-layer computational model with dual rough interfaces was developed to systematically analyze the synergistic effects of interfacial pressure, surface emissivity, and thermal interface materials (TIMs). Surface reconstruction using experimental measurement data generated two representative roughness models to quantify the impact of surface roughness on heat dissipation. Numerical simulations demonstrate that the absence of TIMs leads to insufficient thermal dissipation capacity under ultra-high heat flux conditions. Compared to TIM application, More >

Ahmed Mohamed Galal^1,2, Adebowale Martins Obalalu³, Akintayo Oladimeji Akindele⁴, Umair Khan^5,6, Abdulazeez Adebayo Usman⁷, Olalekan Adebayo Olayemi⁸, Najiyah Safwa Khashi’ie^9,*

CMES-Computer Modeling in Engineering & Sciences, Vol.142, No.3, pp. 3089-3113, 2025, DOI:10.32604/cmes.2025.061296 - 03 March 2025

Abstract The need for efficient thermal energy systems has gained significant attention due to the growing global concern about renewable energy resources, particularly in residential buildings. One of the biggest challenges in this area is capturing and converting solar energy at maximum efficiency. This requires the use of strong materials and advanced fluids to enhance conversion efficiency while minimizing energy losses. Despite extensive research on thermal energy systems, there remains a limited understanding of how the combined effects of thermal radiation, irreversibility processes, and advanced heat flux models contribute to optimizing solar power performance in residential… More > Graphic Abstract

V. I. Zhukov^1,2,*, A. N. Pavlenko¹

Frontiers in Heat and Mass Transfer, Vol.22, No.6, pp. 1761-1775, 2024, DOI:10.32604/fhmt.2024.056779 - 19 December 2024

Abstract The results of an experimental study on critical heat fluxes (CHF) during the nucleate boiling of the HFE-7100 dielectric liquid in horizontal layers of different heights at atmospheric pressure are presented. The existence of a critical layer height has been established. In layers above the critical layer height, a hydrodynamic boiling crisis occurs; in thinner layers, a surface drying crisis occurs. At a layer height equal to the critical value, a dry spot first appears, followed by transition boiling, which gradually spreads to the entire heating surface. In these experiments, the critical layer height was 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

Ahmed Mustaffa Saleem, Abdullah A. Badr, Bahjat Hassan Alyas, Omar Rafae Alomar^*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1231-1244, 2024, DOI:10.32604/fhmt.2024.053770 - 30 August 2024

Abstract This study numerically involves the performance of thermal insulation of different types of composite walls and roofs to demonstrate the best model that can be used for energy-efficient building construction in Iraq. The mathematical model is solved by building its code using the Transmission Matrix Method in MATLAB software. The weather data of 21st July 2022 in Baghdad City/Iraq is selected as a test day. The wall types are selected: the first type consists of cement mortar, brick, and gypsum, the second type consists of cement mortar, brick, gypsum, and plaster and the third type… More >

Mahzad Ahmed¹, Raja Mussadaq Yousaf², Ali Hassan^3,4,*, B. Shankar Goud⁵

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1261-1276, 2024, DOI:10.32604/fhmt.2024.048091 - 30 August 2024

Abstract In the current work, inclined magnetic field, thermal radiation, and the Cattaneo-Christov heat flux are taken into account as we analyze the impact of chemical reaction on magneto-hydrodynamic Casson nanofluid flow on a stretching sheet. Modified Buongiorno’s nanofluid model has been used to model the flow governing equations. The stretching surface is embedded in a porous medium. By using similarity transformations, the nonlinear partial differential equations are transformed into a set of dimensionless ordinary differential equations. The numerical solution of transformed dimensionless equations is achieved by applying the shooting procedure together with Rung-Kutta 4th-order method… More >

Mustafa Abdullah^*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 141-156, 2024, DOI:10.32604/fhmt.2024.046788 - 21 March 2024

Abstract This study investigates the influence of periodic heat flux and viscous dissipation on magnetohydrodynamic (MHD) flow through a vertical channel with heat generation. A theoretical approach is employed. The channel is exposed to a perpendicular magnetic field, while one side experiences a periodic heat flow, and the other side undergoes a periodic temperature variation. Numerical solutions for the governing partial differential equations are obtained using a finite difference approach, complemented by an eigenfunction expansion method for analytical solutions. Visualizations and discussions illustrate how different variables affect the flow velocity and temperature fields. This offers comprehensive More >

Dewi Puspitasari¹, Diah Kusuma Pratiwi¹, Pramadhony Amran², Kaprawi Sahim^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 305-315, 2024, DOI:10.32604/fhmt.2023.041882 - 21 March 2024

Abstract The natural convection from a vertical hot plate with radiation and constant flux is studied numerically to know the velocity and temperature distribution characteristics over a vertical hot plate. The governing equations of the natural convection in two-dimension are solved with the implicit finite difference method, whereas the discretized equations are solved with the iterative relaxation method. The results show that the velocity and the temperature increase along the vertical wall. The influence of the radiation parameter in the boundary layer is significant in increasing the velocity and temperature profiles. The velocity profiles increase with More >