A Method of Hub Vibratory Load Prediction under High Speed State

The research of hub vibratory loads is a very complicated problem of blade aeroelastic response. Based on the airflow environment of blade, the method of hub vibratory loads prediction will be produced when the helicopter flights forward with high speed. It involves the Leishman-Beddoes unsteady model and dynamic stall model, the dynamic inflow theory, the Piters He generalized dynamic wake theory, elastic flap movement of blade and so on. The State-Space method is used to solve the equation, which is fit for numerical calculation. Comparing calculational results of several models, it is revealed that the distributions of rotor wake and blade dynamic response have great influence upon the hub vibratory loads prediction.