低速长航时无人机垂直突风过载分析

Computation of Longitudinal Gust Load for a Low Speed Long Endurance UAV

低速中空长航时无人机的升力非线性较强,利用标准离散突风模型和连续紊流模型计算得到的突风过载差别较大。针对该问题,本文采用改进的离散突风模型求解突风载荷,即直接求解突风条件下原始的运动学方程,并在运动历程中考虑非线性升力的影响。结果表明:改进的离散突风模型计算得到的突风载荷明显低于标准离散突风模型所得的载荷,更贴近无人机的实际情况,且改进的离散突风模型与连续紊流模型的计算结果也相近。

There is a significant gust-loads difference between the normal discrete-gust model and continuous-tur-bulence model because of the strong lift nonlinearity of a low speed medium altitude long endurance （MALE） UAV. To solve this problem, an improved discrete-gust model is adopted,namely,the kinematic equation of gust load is solved and the nonlinear lift is also considered during the moving course. Result indicates that the gust load obtained by the improved method is smaller than that by normal discrete-gust model, and which is close to the actual gust load. At the same time, the gust load is accordance with that computed by continuous- turbulence model.