Efficient and reliable cooling is essential for ensuring the safety and performance of battery packs in electric vertical takeoff and landing (eVTOL) aircraft. To address the limitations of existing cooling methods in cooling capability and structural integration, this study proposes a hybrid cooling system combining air cooling, high-thermal-conductivity plates (HCPs), and phase-change material (PCM). The power demand in different eVTOL flight phases is first analyzed. A single-cell simulation model is then developed and validated through experiments. The effects of three key structural parameters on system performance are investigated, and their relative importance is quantified using sensitivity analysis. A multi-objective evaluation framework is further established to compare the proposed system with no cooling, passive cooling, and liquid cooling strategies. The adaptability of the hybrid cooling system under different operating conditions is also evaluated. Finally, an air-cooling intervention strategy is proposed based on the PCM liquid fraction. The results show that the optimized hybrid cooling system limits the maximum battery temperature and maximum temperature difference to 37.9 °C and 3.1 °C, respectively. Compared with passive cooling, the proposed system improves temperature stability by 44.6%. Compared with the liquid cooling system, space occupancy is reduced by 19.5%, and the grouping efficiency is increased by 22.4%. The adaptability analysis indicates that the optimized system is suitable for ambient temperatures not exceeding 30 °C. In addition, the proposed air-cooling intervention strategy reduces the air-cooling energy consumption by 43.3% compared with continuous air cooling, while maintaining temperature uniformity. These findings provide a numerical reference for the preliminary design of eVTOL battery cooling systems.
Yang et al. (Thu,) studied this question.