Heat transfer augmentation in microchannel heat sink based on isogeometric topology optimization framework

Abstract

This paper focuses on a design problem of branching microchannel heat sink based on solving the thermal-fluid problem in isogeometric analysis approach. A brand new topology optimization framework is proposed to determine the distribution of the microchannels, which comprises two coupled computational layers: the upper layer for channel geometry representation and the lower layer for cooling analysis. In the upper layer, several flexible components fitting two Bézier curves as the central line describe the geometry explicitly, which is quite different from the implicit and conventional level-set description ways of topology optimization, fully releasing the deformation ability of the components. By moving, rotating, deforming, bending, overlapping and merging the level-set-based components, the channel geometry gene-rates and is ready to be projected onto the lower layer for the physical field analysis purpose. The lower layer is discretized using a NURBS patch, and NURBS-based isogeometric analysis is adopted to solve the coupled thermal-fluid problem in the structure and calculate the structural sensitivity so as to drive the upper layer to iterate. Comparing with the conventional topology optimization methods, the proposed method has obvious advantages in terms of computational effectiveness and geometry description. A design of multi-layer cold plate is constructed under this framework, aiming at obtaining the best heat dissipation effect under the constraints of volume dissipation and pressure drop. In the final, simulations and experiments are performed to demonstrate these advantages of this framework.