Hybrid porous media and fluid domain modeling strategy to optimize a novel staggered fin heat sink design

Abstract

In this paper, we propose a novel lid-integrated cold plate with distributed fluid delivery architecture to a silicon microchannel heat exchanger. The microchannels consist of a staggered fin array. The manifold topology tolerates the use of a one-component lid, compatible with high volume fabrication processes, such as injection molding. A multi-scale modelling methodology based on the porous media approximation is introduced and compared with experimental results. The fluid cavity of the heat exchanger in the full heat sink model is represented as a two-dimensional porous domain. This approximation reduces the computational cost to solve the conjugate heat and mass transfer problem significantly. The characteristic of the cold plate is discussed based onfull heat sink model results. The main pressure drop of 93%for the base-line case can be attributed to the losses in the staggered fin array. The flow non-uniformity in the heat exchanger is less than 1.2% A sensitivity analysis with the objective o.f reducing the pumping power for a nominal thermal performance was performed based on a lumped model. it is preferable to increase the number of sub-sections and to reduce the fin dimension in the heat exchanger. The increase in access slit width is of moderate importance. The optimal case computed has 100 pm wide microchannelfins, accessed by 8 manifold.fingers that have 400 pm wide slits at their bottom. This case requires 0.5 W pumping power for a thermal resistance of 12 Kmm2/W.