Study on the lift and propulsive force shares to helicopter

To investigate the effects of lift and propulsive force shares on flight performance, a compound helicopter model is derived. The model consists of a helicopter model, a wing model and a propeller model. At a low speed of 100 km/h, the Lift-to-Drag ratio(L/D) of the compound helicopter is improved when the wing provides 20.2% of the take-off weight. At high speeds, the L/D can be improved when the propeller provides the total propulsive force. Lowering the main rotor speed increases the wing lif...

Study on the lift and propulsive force shares to improve the flight performance of a compound helicopter

To investigate the effects of lift and propulsive force shares on flight performance,a com-pound helicopter model is derived.The model consists of a helicopter model,a wing model and a propeller model.At a low speed of 100 km/h,the Lift-to-Drag ratio(L/D)of the compound heli-copter is improved when the wing provides 20.2％of the take-off weight.At high speeds,the L/D can be improved when the propeller provides the total propulsive force.Lowering the main rotor speed increases the wing lift share,however,the maximum L/D increases first and then decreases.The maximum L/D increases with decreasing the blade twist of the main rotor.Decreasing the blade twist from-16° to-8° increases the maximum L/D by 2.3％,and the wing lift share is increased from 65.0％to 74.7％.When the main rotor torque is balanced by the rudder,the maximum L/D is increased by 2.2％without changing the wing lift share.The wing should provide more lift as increasing the take-off weight,which reduces the induced power of the main rotor and increases the L/D.When increasing the take-off weight from 9500 kg to 11000 kg,the maximum L/D is increased by 6.5％,and the wing lift share is increased from 74.7％to 80.2％.