Improving Thermal Performance of Rectangular Microchannel Heat Sinks using Porous Layer: CFD Simulation and Optimization

Abstract

Microchannel heat sinks are very widely used due to their high heat transfer coefficients and low refrigerant requirements. Nevertheless, microchannel heat sinks still perform sub-optimally when it comes to thermal performance. Therefore, this paper investigates the individual and combined impacts of different characteristics of porous media on the thermal performance of microchannel. Four porosity values are considered: 0.8, 0.85, 0.9, and 0.95. The evaluation is based on three-dimensional computational fluid dynamics simulations. Due to the large number of degrees of freedom in this study, Constructal Theory and Design of Experiments are employed. In this study, the response surface type is Genetic Aggregation, while the Latin Hypercube Sampling algorithm is used for data sampling and Genetic algorithm is used for optimization. Combining porous layers with microchannel heat sinks reduces maximum temperatures about 3K. It is also observed that a lower maximum surface temperature is achieved in the cases with less porosity. Furthermore, the optimal geometry and size of the microchannels with porous layers are determined.

Keywords

• heat transfer
• porous layer
• microchannel heat sinks
• constructal theory
• optimal geometry