Research on the mechanism of heat transfer enhancement in microchannel heat sinks with micropin fins

Abstract

Summary In this paper, the pressure drop and heat transfer features of a microchannel applying micropin fins are investigated by numerical simulations and experiments. The microchannel, which is 20‐mm long, 2.7‐mm wide, and 0.3‐mm deep, is fabricated with copper and consisted of staggered diamond micropin fins. The visualization experiments, by means of the advanced technology micro‐particle image velocimetry (PIV), are conducted to discuss the mechanism of heat transfer by analysing the flow regimes. Meanwhile, 3D‐coupled numerical simulations are applied for the combination with experiments in this research. It is found that the vortex‐wake flow is stable at Reynolds number (Re) = 0 to 300, and a steady recirculating zone can be observed in the wake, where a pair of symmetrical vortices is formed. All the time, the vortex‐wake flow is unstable at Re = 300 to 650. Under this situation, it is due to the decrease of vorticity that the Nusselt number (Nu) is not significantly increased as it was expected. Thus, when Nu in the pin fin microchannel is predicted, the vorticity should be considered as well as turbulent kinetic energy (TKE). Furthermore, comparative study was carried out based on the mechanism proposed in this study among three kinds of microchannel with different fins, including staggered circular pin fins (CPF), square pin fins (SPF), and diamond pin fins (DPF).

Thermal performance and entropy generation of single‐layer and double‐layer constructal Y‐shaped bionic microchannel heat sinks

“…A large number of researchers have devoted to design a variety of chips cooling technologies and published a series of results. [4][5][6][7][8][9][10][11] For example, the thermal behaviors of the rectangular straight microchannel (RSMC) subject to the laminar flow regime were investigated by Lee et al 6 whose results indicate wide disparities occur between experiments and correlations due to mismatch in the boundary and inlet conditions. Yet, with full 3D conjugate analysis coupled with entrance and boundary conditions, the performance of RSMC can be well predicted.…”