Topology optimization of liquid-cooled plates for enhanced thermal management of eVTOL battery packs

Electric vertical take-off and landing (eVTOL) aircraft represent a major breakthrough in sustainable aviation. The vertical flight phase generates non-linear transient extreme heat, and conventional liquid-cooled cold plates exhibit severe limitations under such stringent constraints. Regular geometric flow channels are highly prone to local hotspot accumulation, which in turn exacerbates temperature non-uniformity within the battery pack. This study presents a liquid-cooled cold plate configuration generated via topology optimization under extreme thermal conditions. Specifically, four topological structures with different inlet/outlet configurations were first evaluated to determine the optimal design based on temperature weighting and Reynolds number (Re). To ensure simulation accuracy, a 1D-3D coupled electrochemical-thermal model was adopted to capture precise heat generation rates during high-rate, short-duration discharge. Subsequently, a 3D electrochemical-thermal-fluid coupling model was established to analyze flow and heat transfer characteristics. The results show that the configuration optimized with a temperature weight of ω = 0.4 and Re = 100 (designated as Case D) achieves the best performance. At a flow rate of 0.25 m/s, compared with a traditional cold plate, the optimized design reduces the maximum temperature by 3.7 K and the temperature standard deviation by 32%, while increasing the Nusselt number (Nu) by 96%. Experimental validation further confirmed that, relative to parallel-channel designs, the topology-optimized cold plate lowers the average temperature by 1.9 K and the maximum temperature difference by 0.8 K. This proposed scheme demonstrates superior cooling efficiency over conventional solutions, providing a vital reference for eVTOL battery thermal management system design.