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.