Design complexity tradeoffs in topology optimization of forced convection laminar flow heat sinks

This paper demonstrates that there is much more to gain from topology optimization of heat sinks than what is described by the so-called pseudo 3D models. The utilization of 3D effects, even for microchannel heat sinks is investigated and compared to state-of-the art industrial designs, for a microelectronic application. Furthermore, the use of design restrictions in the optimization framework demonstrates that the performances of microchannel heat sinks are highly dependent on the ability to provide complex refrigerant distribution and intricate flow paths through the heat sink. The topology optimized microchannel heat sinks are exported from a voxel mesh to bodyfitted mesh using Trelis Sculpt and imported into a commercial CFD software. A systematic comparison with the state-of-the art industrial design shows that the temperature elevation of the microelectronic chip can be reduced by up to 70%, using a 3D topology optimized microchannel heat sink. Restricting the design freedom, for example, by limiting the solid features to be unidirectional downgrades the performances of the optimized microchannel heat sinks but still outperforms the reference case, for a similar design complexity.