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 - 11 July 2024

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 >

Amnart Boonloi¹, Withada Jedsadaratanachai^2,*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 317-336, 2023, DOI:10.32604/fhmt.2023.044929 - 30 November 2023

Abstract Thermal performance enhancement in a square channel heat exchanger (HX) using a passive technique is presented. Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvement. The vortex turbulator of interest is discrete X-V baffles (XVB). The discrete XVBs are inserted in the square channel with the main aim of generating vortex flow. The vortex flow generated can support the enhanced convective heat transfer coefficient and also enhance HX performance. Effects of baffle configuration (type A and B), baffle size (w/H = 0.05, 0.10, 0.15 and 0.20), baffle… More > Graphic Abstract

O. M. Oyewola^a,b,* , M. O. Petinrin^a , and H. O. Sanusi^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.16

Abstract The flow and heat transfer behaviour of channels with dimples and protrusions of spherical and piriform shapes was numerically explored by solving the Navier-Stokes and energy equations with a CFD software, the ANSYS Fluent 19.3, in the range of Reynolds numbers from 8,500 to 59,000. The values of the Nusselt number and friction factors were estimated and the non-dimensional Performance Evaluation Criterion (PEC) was determined to measure the thermal-hydraulic performance. The results reveal that the piriform protruded channel demonstrated a higher thermal performance with Nusselt number values of 36%, 15%, 23%, and 9% than the… More >

M. O. Petinrin^a , B. A. Sikirullahi^a, T. T. Olugasa^a, O. M. Oyewola^a,b,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.28

Abstract Tubes are commonly employed in heat exchangers for their ease of production and capacity to sustain high pressure. In this study, the heat and flow transfer behaviour of cam-shaped tube bank in staggered configuration at varying angles of attack 0°to 180° was numerically investigated. The study was carried out by solving the continuity, momentum, energy and realizable k-ε transport equations using the finite volume-based ANSYS Fluent solver. This was performed to acquire the friction factor and heat transfer characteristics in the air inlet velocity range of 9 to 15 m/s. The results showed that the… More >

Yukun Lv, Zhuang Wei^*, Quanzhi Ge, Fan Yang, Shuang Yang

Energy Engineering, Vol.118, No.6, pp. 1855-1867, 2021, DOI:10.32604/EE.2021.015248 - 10 September 2021

Abstract The water-cooling heat dissipation technology can solve the heat dissipation and noise problems of the calculation plate. Therefore, the structural design of the water-cooling plate directly affects its flow and heat transfer characteristics, which restricts the promotion and application of the technology. To this end, the water-cooling plate of a heat dissipation system was taken as the research object, and its flow and heat transfer characteristics were numerical simulated and experimental studied. Through comparative analysis, the rationality of the numerical simulation method was verified. Based on this, three improved schemes of water-cooling plate structure were More >

Cong Qi^1,2,*, Chengchao Wang^1,2, Jinghua Tang^1,2, Dongtai Han²

Energy Engineering, Vol.117, No.2, pp. 63-78, 2020, DOI:10.32604/EE.2020.010433 - 23 April 2020

Abstract Because of the poor thermal performance of ordinary tubes, a triangular tube was used to replace the smooth channel in the heat transfer system, and nanofluids were used to take the place of ordinary fluids as the heat transfer medium. High stability nanofluids were prepared, and an experimental set on flow and heat exchange was established. Effects of triangular tube rotation angles (α = 0°, 30°, 60°) as well as mass fractions of nanofluids (ω = 0.1%, 0.3%, 0.5%) on heat exchange and flow performance were experimentally considered at Reynolds numbers (Re = 800–8000). It… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-18, 2019, DOI:10.5098/hmt.13.23

Abstract The purpose of the present work is to study flow configuration and heat transfer behavior in a square channel heat exchanger equipped with C-shaped baffle. The influences of flow attack angle and baffle size on flow and heat transfer characteristics are considered for the laminar flow regime with the Reynolds number around 100 – 2000. The numerical study with finite volume method is selected for the present investigation. The SIMPLE algorithms is opted to solve the numerical problem. The numerical results are concluded in terms of flow and heat transfer mechanisms in the tested section.… More >