Solar powered unmanned aerial vehicle (UAV), achieving a long time flight, has been drawn attention. The energy management is a dominate role to determine the comprehensive performance of the solar powered UAV. In this work, a three dimensional numerical model is built to study the heat and mass transfer in the solar powered UAV at the extreme condition. The effects of flight velocity, flight attitude, day and light on the heat and mass transfer in the solar powered UAV are investigated in details. Then, an improved energy management strategy is proposed to improve the efficiency of the energy utilization for UAV. Results show that the temperature in the solar powered UAV is affected by the flight altitude. When the flight altitude varies from 11 km to 20 km, the temperature of the battery has approximately decreased by 5 K. The improved thermal management system can keep the battery temperature at about 220 K. The minimum temperature of the battery approximately increases by 50 K compared with the traditional structure. The heat transfer in the solar powered UAV is strengthened with the improved structure. Besides, the outer surfaces of the UAV are also influenced by the improved structure with the minimum temperature of the solar panel increased by 3 K. The data obtained from the analysis of the simulation results are helpful to the optimal design of global energy management.

实现长时间飞行的太阳能无人机（UAV）备受关注。能源管理是决定太阳能无人机综合性能的主导作用。在这项工作中，建立了三维数值模型来研究太阳能无人机在极端条件下的传热传质。详细研究了飞行速度、飞行姿态、日光和光照对太阳能无人机传热传质的影响。然后，提出了一种改进的能源管理策略，以提高无人机的能源利用效率。结果表明，太阳能无人机的温度受飞行高度的影响。当飞行高度从 11 公里到 20 公里变化时，电池温度大约下降了 5 K。改进后的热管理系统可使电池温度保持在220 K左右，电池最低温度比传统结构提高约50 K。太阳能无人机中的传热通过改进的结构得到加强。此外，无人机的外表面也受到改进结构的影响，太阳能电池板的最低温度增加了3 K。从仿真结果分析获得的数据有助于全球能源管理的优化设计。