Forced convection heat transfer in the microchannel heat sink for electronic equipment cooling

Abstract

In this paper, analytical solutions for fluid flow and heat transfer through microchannel heat sinks are presented by using the porous medium approach. Using the analytical solutions, parametric study for velocity and temperature distributions, optimization of the thermal performance of the microchannel heat sink, and discussion on the applicability of the one-equation model in the microchannel heat sink are conducted. In Chapter 2, the microchannel heat sink is modeled as a porous medium. Analytical solutions are obtained based on the Brinkman-extended Darcy flow model and the two equation model for heat transfer. The closed-form solution for fluid flow and the numerical solutions for conjugate heat transfer are also obtained and compared with analytical solutions to validate the porous medium approach. Using the analytical solutions, variables of engineering importance are identified and their effects on fluid flow and heat transfer are studied. Also, the expression for total thermal resistance is derived from the analytical solutions and is minimized in order to optimize the thermal performance of the microchannel heat sink. In Chapter 3, analytical solutions for temperature distribution are obtained by using both one-equation and two-equation models for the case dealt with in chapter 2. From the analytical solutions, variables of engineering importance are identified and their effects are studied. To check the validity of the local thermal equilibrium(LTE hereafter) assumption, relative temperature difference between the phases is defined and its distribution with respect to the variables of engineering importance is plotted by using the analytical solutions. Additionally, the asymptotic behavior of the relative temperature difference between the phases is studied by using the order of magnitude analysis to confirm the overall tendency in relation to the validity of the one-equation model. Finally, the distribution of the relative temperature difference bet...