Torsion of blade with trailing-edge flap under air loads

The method of twisting the blade using a trailing-edge flap is presented in this paper. The dynamic model of the rotor blade with the trailing-edge flap is developed based on the modified Greensberg quasi-static aerodynamic theory. The effect of flap deflection on the torsion of the blade is investigated. Results show that the angles of torsion are equal to -3.8° and 3° when the flap deflection is 6° and-6°, respectively. The flap deflection has a powerful effect on the blade bending deformation in flapping direction. When the flap deflection is 6°, the tip flapping displacement is 0.16 R. It is decreased by 50.8% in comparison with that without any flap deflection. So it is feasible to twist the blade by using the trailing-edge flap.