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 - 11 July 2024

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 >

Yasushi Koito^1,*, Shoma Hitotsuya², Takamitsu Takayama², Kenta Hashimoto²

Frontiers in Heat and Mass Transfer, Vol.21, pp. 33-46, 2023, DOI:10.32604/fhmt.2023.041829 - 30 November 2023

Abstract An ultra-thin flattened heat pipe has been developed with a centered wick structure. This structure is essential to make the heat pipe thinner. However, the centered wick structure reduces the evaporation and condensation surface areas of the wick structure because it is sandwiched between heat pipe walls. In this study, because detailed discussion has not been made, heat transfer experiments were conducted for the wick structure sandwiched between two solid walls. This study focused on the evaporation heat transfer characteristics from the sandwiched wick structure. The experiments were conducted with three wick structures, that is,… More >

Yasushi Koito^a,*

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-7, 2021, DOI:10.5098/hmt.16.1

Abstract For ultra-thin heat pipes, a centered wick structure is often used. In this study, a numerical analysis is performed on an ultra-thin heat pipe in which the wick structure’s position has deviated from the center. A 3D heat pipe model, developed by the author in a previous study, is extended, and numerical calculations are conducted to determine any differences in performance because of an off-center wick. The major findings are as follows: (1) a completely centered wick structure is recommended for optimum performance; (2) accurate central positioning of the wick structure is important in the More >