Optimisation of single and double layer counter flow microchannel heat sinks

In this paper, a single layer counter flow (SLCF) and a double layer counter flow (DLCF) microchannel heat sink with rectangular channels have been modelled by employing the thermal resistance network with the correlations available in the open literature to evaluate the performance of the heat sinks. The accuracy of the prediction has been verified by comparing the results obtained with those from the more comprehensive three dimensional computational fluid dynamics (CFD) conjugate heat transfer model. Good agreements were obtained. The thermal resistance models has been linked with a multivariable constrained direct search optimisation algorithm to optimise the performance of the SLCF and DLCF microchannel heat sink under a set of design constraints. Optimisation results show that both the SLCF and DLCF heat sinks operating in the laminar out performed the heat sinks under turbulent flow conditions, both in heat transfer and hydrodynamic considerations.