Heat Transfer Capacity of Lotus-type Porous Copper Heat Sink for Air Cooling

Abstract

Lotus-type porous metal with many straight pores is attractive as a heat sink because larger heat transfer capacity is obtained due to the small diameter of the pores. The heat transfer capacity of the lotus-type porous copper heat sink was calculated using the model with the pores of uniform diameters. However, actual lotus-type porous metals have a distribution of pore diameter. In the present work, we investigated the lotus-type porous copper fin model (non-uniform pore model) by considering size distribution of measured on the actual measurement of the pore diameters on a cross-section of the lotus-type porous copper fin. Prediction of the heat transfer characteristics for the lotus-type porous copper heat sink shows a good agreement with the experimental data. In addition, the predicted heat transfer coefficient of non-uniform pore model also shows a good agreement with the uniform pore models. Thus, it is clarified that the heat transfer characteristic of the lotus-type porous copper heat sink can be predicted by the uniform pore model.

Strongly Orthotropic Open Cell Porous Metal Structures for Heat Transfer Applications

“…The lotus-type structure was first investigated as a metal sponge structure by Shapovalov et al [12], earlier investigations only thought about the pores as a casting defect. Nakajima and its collaborators refined the production method and intensified their characterization [13][14][15][16]. Today, there are many different manufacturing methods for lotus-type structures, which can be split in major fabrication techniques.…”

“…Here, a through-flow is possible only in the direction of the pores; therefore, it is impossible to optimize the heat transfer in applications requiring a fluid flow by changing the orientation of the lotus-type structure. The flow of a fluid in the direction of the pores was experimentally tested and compared to analytical model predictions by Chiba et al [13]. They tested the pressure drop of lotus-type structures, which were cut perpendicular to the elongation of the pores into plates of different thickness.…”

Immersion Cooling of Electronics Utilizing Lotus-Type Porous Copper

“…These heat transport technologies are currently introduced for cutting-edge high-performance personal computers, E16-013-2 Although the porous media can be generally classified into particle-sintered porous media, porous foam, fibrous porous media, porous mesh, etc., lotus porous media with uni-directional porous structure have been developed recently. [20,21] The feature of the lotus porous media is higher effective thermal conductivity in the pore direction and higher permeability due to the uni-directional pore structure, compared with the other porous media as shown in Fig. 1, which conceivably leads to further enhancement of the boiling heat transfer due to high fin effect.…”

Immersion cooling of electronics utilizing lotus-type porous copper

“…1, the porous media can be classified into particle-sintered porous media, porous foam, fibrous porous media, porous mesh, etc. Recently, lotus porous media with the uni-directional porous structure have been developed [10,11]. The feature of this lotus porous media is the unidirectional porous structure which provides highly effective thermal conductivity toward the pore direction, which has a potential of reducing the temperature difference in the nucleate boiling heat transfer regime.…”