Dynamic response simulation of helicopter in variable wind field

The dynamic response of helicopters induced by spatial and temporal varied wind is vital to helicopter performance and safety during the low-altitude flight. Firstly, an affine nonlinear dynamic model is constructed for helicopter’s flight dynamic system. Then, a wind model considering both its temporal derivative and spatial gradient is derived to describe the variable wind field. Afterwards, the Runge-Kutta algorithm is employed to simulate the dynamic response in a time-marching scheme. A trim analysis of UH-60 helicopter is applied to validate the nonlinear flight dynamic model. Based on these, the flight dynamics of helicopters due to discrete gust and low-altitude wind shear is simulated, in order to investigate the influence of variable wind to helicopter’s response. Results indicate when the helicopter enters into discrete gust field, temporal derivative of wind has a dramatic impact on response when the flight speed increases. When helicopter experiences a low-altitude wind shear, spatial gradient of wind has an increasing impact on response as flight altitude decreases.