Topology optimization of cold plate for battery thermal management based on length scale control

The topology optimization cold plates play an important role in ensuring the safety and performance of batteries. However, there are some difficulties in processing due to the uneven width of flow channel. The length scale control can control the channel width through adding constraints. In this study, the maximum and minimum length scale control in topology optimization is carried out by using the twice-filtration projection method to optimize the channel of cold plate. The results show that there is no narrow or wide channel with the increase of minimum length scale control size rmin and the decrease of maximum length scale control size rmax when the twice-projection point is 0.7 and twice-projection slope is 8. The performance evaluation coefficient increases due to the enhancement of Nusselt number and reduction of flow resistance coefficient when rmin decreases and rmax increases. The maximum temperature, maximum temperature difference and pressure drop of optimized cold plate with length scale control (SCOCP) are 34.53 K, 35.47 K and 0.08 Pa lower than those of traditional cold plate, respectively. The flow channel structure of SCOCP is simpler than that of optimized cold plate without length scale control (OCP). Then, the small gap between SCOCP and OCP in performance is compensated by local length scale control. Finally, the numerical model and comparison of three cold plates are verified by experiments. The experimental relative deviation of temperature and pressure drop are within 4 % and 10 %, respectively. It is significant to simplify the processing of cold plate through employing length scale control method.