Analysis of porous medium model for microchannel heat sinks and Its Application

Chen Qiang  Yang Jingyu

(Department of Computer Science and Techmology, Nanjing University of Science and Technology, Nanjing 210094)

Dong Tao  Chen Yunsheng

(School of Mechanical Engineering, Nanjing Unive- rsity of Science and Technology, Nanjing 210094)

Ge Xiaohong  Xie Jianfang

(State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information, Shanghai 200050)

Abstract: Based on the Brinkman-extended Darcy Equation, both double-equation resolving model and mono-equation resolving model for fluid flow in micro scale are designed. The analytical solutions for the velocity and the temperature profiles of fluid flow in microchannel are obtained and compared by abstracting the microchannel heat sinks as a block of fluid-saturated porous medium. Furthermore, the effects of aspect ratio and the effective thermal conductivity ration on fluid flow and heat transfer in microchannel are analyzed. It is proved that the analytical solutions of both the double-equation and mono-equation resolving models can predict the volume average profiles of the velocity and the temperature in microchannel. Notably, it is focused that the double-equation resolving porous medium model can predict the total thermal resistance and optimize the structure performance of the microchannel heat sinks. The optimized microchannel heat sinks is manufactured on the silicon wafer through multiplex inductively coupled plasma etching. On the condition of local thermal equivalence, the mono-equation resolving porous medium model can be used in practical calculation expediently without depending on the heat transfer coefficients, which can only be obtained in experiments.

Key words:  Micro scale  Heat transfer   Microchannel  Heat sinks  Porous medium

CLC No: TH297

国家自然科学基金(50176039)和“十五”国防重点预研(40404070101)资助项目. Received 30205, received in revised form 20030915