A porous medium approach for the thermal analysis of microchannel heat sinks

Purpose – The purpose of this paper is twofold: to show the applicability of the porous medium approach (PMA) to the thermal analysis of liquid-cooled microchannel heat sinks with nonuniform flows and/or complex geometries, and to present an original method for circumventing the limitations of the local thermal non-equilibrium (LTNE) model of Ansys Fluent, which does not allow to account for the heat exchanges between the porous medium and the attached solid walls. Design/methodology/approach – The PMA proposed in this study is based on the use of the local thermal non-equilibrium model implemented in the Ansys Fluent software package and empirical coefficients for the evaluation of the heat transfer coefficient at the fluid/porous medium interface through a calibration procedure. The validation of the model is carried out by comparison of the results obtained with the proposed approximate method and those of accurate CFD simulations. Findings – The results prove the reliability of the proposed method, which yields predictions that are accurate enough for practical purposes but with significantly reduced computational effort compared to that required by simulations conducted using traditional CFD methods. Originality/value – The originality of the presented method lies in proposing, for the simulation of flow and heat transfer in liquid-cooled microchannel heat sinks, the use of the PMA combined with the empirical determination of the heat transfer coefficient at the fluid/porous medium interface and the method used to adapt the Ansys Fluent LTNE model for this purpose.