旋翼结冰模型与纵列式直升机平衡特性分析

为了研究纵列式直升机结冰后的飞行动力学问题,基于CFD(ComputationalFluid Dynam ics)技术提出了旋翼结冰的理论模型;基于旋翼冰风洞试验数据,考虑桨叶表面附着冰脱落及桨叶表面局部温度对结冰的影响,提出了旋翼结冰的工程模型.建立了纵列式直升机结冰后的飞行动力学模型,研究了不同飞行速度条件下结冰对样机CH-47B平衡特性的影响,分析了环境温度、结冰时间、液态水含量以及平均水滴直径对旋翼扭矩的影响.计算结果的对比分析显示:两种结冰模型在计算精度上基本一致,表明结冰模型合理,能够用来进行结冰后的飞行动力学分析,为纵列式直升机结冰后的飞行动力学研究奠定了基础.

Rotor icing model and trim characteristics analysis for tandem helicopter

A theoretical rotor icing model was proposed based on the computational fluid dynamics (CFD) technique to study the tandem rotor helicopter dynamics due to icing. Considering the rotor blade ice shedding and local temperature variation on the rotor blade, another engineering rotor icing model was advanced based on the rotor icing tunnel data. The model of the tandem rotor helicopter dynamics due to icing was built and the trim characteristics of CH-47B due to icing at the hover and in the forward flight were analyzed. The effect on the rotor torque due to temperature, icing time, liquid water content and median volumetric diameter in the icing condition was computed. The agreement between the theoretical rotor icing model and the engineering method indicates that the models are feasible and effective, and they can lay the foundation of the research about the tandem helicopter dynamics in the icing condition.