翼尖间距变化对组合式太阳能无人机气动影响分析

Analysis of influence of wingtip spacing variation on aerodynamic of combined solar UAV

摘要:

采用翼尖链翼的组合式无人机策略，可以有效解决太阳能无人机机翼载荷小、载荷能力差、外形尺寸大以及大展弦比导致的飞机柔性增大等问题。为了探究组合式太阳能无人机对接过程中翼尖涡的变化及其对气动特性和能耗的影响，使用 RANS 控制方程和 SST k-ω 湍流模型的 CFD 方法对某型太阳能无人机展开研究。通过两太阳能无人机在翼展方向上间距缩进，模拟两无人机在空中通过翼尖链翼进行组合的情况。结果表明：两架太阳能无人机翼尖上一对旋向互逆涡从翼尖间距缩小至 20% 平均气动弦长时开始融合，并在形态、特征参数方面发生了改变；翼尖链翼的组合策略使单架太阳能无人机的升阻比最多提升 23.5%，飞行所消耗功率最多减少 12.2%，显示出降低储能电池容量需求、提升太阳能无人机总体性能的前景。

Abstract:

To explore the variations of tip vortices and their influences on aerodynamic characteristics and energy consumption during the docking process of a combined solar-powered unmanned aerial vehicle (UAV), a CFD approach employing the RANS control equation and the SST k-ω turbulence model was utilized to conduct research on a type of solar-powered UAV. Through the reduction of the spanwise spacing between two solar-powered UAVs, the situation where two UAVs combine in the air through tip-linked wings was simulated. The results indicate that a pair of vortices with opposite rotational directions on the wing tips of the two solar-powered UAVs start to merge when the tip spacing is reduced to 20% of the average aerodynamic chord length, and changes occur in terms of morphology and characteristic parameters. The combined strategy of tip-linked wings enables the lift-to-drag ratio of the solar-powered UAV to increase by up to 23.5% and the power consumption during flight to decrease by up to 12.2%, demonstrating the potential for reducing the capacity requirement of energy storage batteries and enhancing the overall performance of solar-powered UAVs.