Kenta Hashimoto¹, Guohui Sun¹, Yasushi Koito^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 687-702, 2024, DOI:10.32604/fhmt.2024.052928

Abstract Centered or striped wick structures have been used to develop ultrathin heat pipes. Differing from traditional heat pipes, the centered or striped wick structures leave noncontact container surfaces with the wick structure. In this study, experiments and numerical analyses were conducted to investigate the influence of these noncontact surfaces. In the experiments, a strip-shaped wick structure was placed vertically, the top was sandwiched between wider rods and the bottom was immersed in a working fluid. The rod width was greater than the wick width; thus, noncontact surfaces were left between the rod and the wick… More >

Karam H. Mohammed¹, Ashraf E. Al-Mirani¹, Bashar Mahmood Ali², Omar Rafae Alomar^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 839-854, 2024, DOI:10.32604/fhmt.2024.052671

Abstract This work involves an experimental study on the performance of automobile air-conditioning systems by adding AlO nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed cooling of refrigeration systems and to compare it with the system operated using only oil. The AlO nanoparticles have been added to the oil compressor for different ranges of mass concentration (Ø = 0.1%, Ø = 0.15% and Ø = 0.2%). The stability of AlO nanoparticles has been tested by direct observation for different time periods. The results indicated that the air conditioning system that More >

Xiaojun Li, Fuyong Su^*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 719-732, 2024, DOI:10.32604/fhmt.2024.051950

Abstract In order to study the effect of oxygen-enriched combustion technology on the temperature field and NO emission in the continuous heating furnace, this paper studies the oxygen-enriched combustion of a pushing steel continuous heating furnace in a domestic company. This study utilizes numerical simulation method, establishes the mathematical models of flow, combustion and NO generation combustion process in the furnace and analyzes the heat transfer process and NO generation in the furnace under different air oxygen content and different wind ratio. The research results show that with the increase of oxygen content in the air, More > Graphic Abstract

S. M. Hosseinalipour^*, S. Asiaei^*, Ammar A. Hussain Al-Taee

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 747-767, 2024, DOI:10.32604/fhmt.2024.051541

Abstract This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact. This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region, especially in Iraq. The study assessed the energy efficiency of dynamic insulation technology by analyzing three wall models (static, dynamic, and modified) during the winter season. This paper expands the analysis to include a hot, dry summer scenario, providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and More >

Ali Abdullah Abbas Baiee, Sasan Asiaei^*, Sayed Mostafa Hosseinalipour^*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 955-976, 2024, DOI:10.32604/fhmt.2024.051532

Abstract Globally, potable water scarcity is pervasive problem. The solar distillation device is a straightforward apparatus that has been purposefully engineered to convert non-potable water into potable water. The experimental study is distinctive due to the implementation of a rotational mechanism within the pyramidal solar still (PSS), which serves to enhance the evaporation and condensation processes. The objective of this research study is to examine the impact of integrating rotational motion into pyramidal solar stills on various processes: water distillation, evaporation, condensation, heat transfer, and energy waste reduction, shadow effects, and low water temperature in saline… More >

Bo Hui^1,2,*, Shengneng Zhu², Sijun Su², Wenjuan Li²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 855-868, 2024, DOI:10.32604/fhmt.2024.051387

Abstract The structure of the concave-convex plates has proven to be crucial in optimizing the internal flow characteristics of the electrolyzer for hydrogen production. This paper investigates the impact of the gradual expansion angle of the inlet channel on the internal flow field of alkaline electrolyzers. The flow distribution characteristics of concave-convex plates with different inlet angle structures in the electrolytic cell is discussed. Besides, the system with internal heat source is studied. The results indicate that a moderate gradual expansion angle is beneficial for enhancing fluid uniformity. However, an excessively large gradual expansion angle may More > Graphic Abstract

Zhisheng Xu^*, Sohail Mahmood, Zihan Yu

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 791-816, 2024, DOI:10.32604/fhmt.2024.051058

Abstract The centralized smoke exhaust system of shield tunnel is an important determinant for tunnel fire safety, and the use of different design parameters of the tunnel smoke exhaust system will affect the smoke exhaust effect in the tunnel, and the influence of different design parameters on the smoke exhaust effect and temperature attenuation of the tunnel can help engineers in designing a more effective centralized smoke exhaust system for the tunnel. In this paper, the Fire Dynamic Simulator (FDS) is utilized to examine smoke exhaust vent settings for a centralized exhaust system in shield tunnel… More >

M. Sridevi¹, B. Shankar Goud², Ali Hassan^3,4,*, D. Mahendar⁵

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 939-953, 2024, DOI:10.32604/fhmt.2024.050929

Abstract This study intends to evaluate the influence of temperature stratification on an unsteady fluid flow past an accelerated vertical plate in the existence of viscous dissipation. It is assumed that the medium under study is a grey, non-scattered fluid that both fascinates and transmits radiation. The leading equations are discretized using the finite difference method (FDM). Using MATLAB software, the impacts of flow factors on flow fields are revealed with particular examples in graphs and a table. In this regard, FDM results show that the velocity and temperature gradients increase with an increase of Eckert More >

Yasushi Koito^1,*, Akira Fukushima²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 869-887, 2024, DOI:10.32604/fhmt.2024.050910

Abstract Thermal and fluid-flow characteristics were numerically analyzed for ultra-thin heat pipes. Many studies have been conducted for ultra-thin heat pipes with a centered wick structure, but this study focused on separated wick structures to increase the evaporation/condensation surface areas within the heat pipe and to reduce the concentration of heat flux within the wick structure. A mathematical heat-pipe model was made in the three-dimensional coordinate system, and the model consisted of three regions: a vapor channel, liquid-wick, and container wall regions. The conservation equations for mass, momentum, and energy were solved numerically with boundary conditions… More >

Md. Fayz-Al-Asad^1,4, F. Mebarek-Oudina^2,*, H. Vaidya³, Md. Shamim Hasan⁴, Md. Manirul Alam Sarker⁴, A. I. Ismail⁵

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 817-837, 2024, DOI:10.32604/fhmt.2024.050814

Abstract The goal of this paper is to represent a numerical study of magnetohydrodynamic mixed convection heat transfer in a lid-driven vertical wavy enclosure with a fin attached to the bottom wall. We use a finite element method based on Galerkin weighted residual (GWR) techniques to set up the appropriate governing equations for the present flow model. We have conducted a parametric investigation to examine the impact of Hartmann and Richardson numbers on the flow pattern and heat transmission features inside a wavy cavity. We graphically represent the numerical results, such as isotherms, streamlines, velocity profiles,… More >