Thermal design of composite cold plates by topology optimization

Topology optimization has been extensively utilized to generate cold plates with efficient cooling performance. However, the design of composite cold plates remains challenging. This study presents a two-solid topology optimization method for conjugate heat transfer based on ordered SIMP (solid isotropic material with penalization). The proposed method aims to develop high-performance composite cold plates by leveraging the differences in thermal conductivity of various materials. The optimization results were investigated for four inlet and outlet combinations at various Reynolds numbers. The results indicate that using a staggered distribution of multiple inlets and outlets yields higher heat transfer than a single distribution. Furthermore, composite cold plates derived from the two-dimensional optimized models were numerically compared with rectangular flow channel and non-composite cold plates. The optimized channels exhibited superior hydrothermal performance over the rectangular flow channel, which was primarily attributed to the weakening of the velocity stagnation region. The average temperature (T¯) and root mean square temperature (RMST) of the heat source were reduced by a maximum of 2.53% and 57.67%, respectively. The friction factor decreased by up to 50.42%. Compared to non-composite cold plates, the decrease in RMST reached 16.24% without any additional increase in the pumping power. Composite cold plates further promote temperature uniformity by accelerating the heat transfer rate through their high thermal conductivity, thereby mitigating the occurrence of hotspots. Finally, the performance of the three test samples was experimentally compared to validate the numerical results. The optimized design enables the strategic allocation of highly thermally conductive material on a cold plate while employing more cost-effective alternatives in other areas. The proposed method is anticipated to expand the design possibilities for cold plates and provide insights into addressing concerns related to hotspots in equipment.