拓展太阳能飞机在较高纬度地区的跨年驻留性能有助于促成太阳能飞机的广泛实用化。建立了适用于任意高度、任意纬度、任意指向的光伏组件面功率模型,并考虑了光伏组件的温度效应,通过能量仿真得出:在方位角跟踪方式下,滚偏角为90°的主动式光伏组件的日均面功率最优。然后在布局与能源综合设计思想指导下,建立了一套基于机翼帆尾的太阳能飞机总体参数设计方法,其组成模块包括各部件质量方程、气动效率方程、用于构建气动布局参数与全机光伏组件面功率特性之间映射关系的Kriging代理模型,以及参与总体参数匹配优化设计的量子粒子群优化(QPSO)算法及其多目标评价函数。面向高纬度与跨年驻留的设计指标,开展了机翼帆尾太阳能飞机的方案实例设计,其中驻留纬度与高度指标分别为45°N和18km。详细分析了此方案在23.5°N~55°N纬度域内的可持续高度包线。研究结果表明:与传统布局形式相比,机翼一帆尾布局形式大幅提升了高纬度地区冬季附近的光伏组件面功率,有效地减小了翼展尺度、机翼面积并提升了巡航速度,具有良好的应用优势。方案设计实例也验证了基于机翼一帆尾的太阳能飞机总体参数设计方法的可行性。
Exploration of the capability of a solar-powered aircraft for year-round station keeping at higher latitudes is of great significance for the enhancement of its operational value. In this paper a model of power area density for PV modules arbitrarily oriented is first established which takes into consideration the temperature of the PV modules, flight altitude, flight latitude, and year-round seasons. The analysis on power absorption shows that the rotation angle of 90° is the optimal in the azimuth tracking method for a pair of sail tails in use. Secondly, a conceptual design methodology of solar-powered aircraft of a wing-sail configuration is developed which integrates the configuration design with energy absorption, and its formulations include mass component parameterization, aerodynamic efficiency, Kriging surrogate model and quantum behaved particle swarm optimization (QPSO) algorithm and its fitness function. Thirdly, a comparison of design methodology is conducted for the wing-sail configuration and wing-only configuration. Finally, a case study of the wing-sail configuration is conducted at the latitude of near 45°N and the altitude of higher than 18 km and its capabilities of operational altitude, payload-carrying and operational latitude in a whole year are investigated from 23.5°N to 55°N. The results show that in contrast with the traditional configuration, the wing-sail configuration improves power absorption characteristics at higher latitudes near winter, shortens the wingspan and reduce the wing area effectively, improves cruise velocity and makes year-round operation at higher latitudes feasible and efficient. These applications demonstrate the validity of the proposed design methodology of primary parameters of the wing-tail configuration solar-powered aircraft.