沙 盲 环 境 直 升 机 桨 叶 磨 损 分 析 方 法

The behavior of helicopter brownout endangers flight safety，induces rotor blade erosion，and reduces its performance. An analysis method of helicopter blade erosion in brownout condition is then proposed. In this method，variations of the sand cloud are simulated by a helicopter brownout model based on a viscous vortex particle method and a discrete element method，a collision and erosion models between blade and sand cloud are coupled，and the characteristics of blade erosion with high velocity is also considered. This work compares with experimental data of plane erosion with different impact velocities，impact angles，and materials，including nickel，SS304 stainless steel，bidirectional Carbon Fiber Reinforced Epoxy（CF/EP），Glass Fiber Reinforced Epoxy（GF/EP），Polyurethane（PU），and Ti-6Al-4V titanium，to validate the accuracy of the present method. The characteristics of blade erosion for the EH-60L helicopter in brownout condition is then analyzed，and the influence of flight speed on the blade erosion is also investigated. As time increases，the collision between the blade and the sand cloud，the blade erosion，and the rotor erosion zone significantly increases in helicopter brownout condition. Furthermore，the erosion in blade tip is significantly worse than inner blade due to the longer exposure time，larger impact velocity and angle. Additionally，the blade erosion and the rotor erosion zone increase firstly and then reduce with increasing flight speed.