Aerodynamic optimization and mechanism design of flexible variable camber trailing-edge flap

Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camber trailing-edge flap is introduced,capable of changing its shape smoothly from 50％ flap chord to the rear of the flap,Using a numerical simulation method for the case of the GA (W)-2 airfoil,the multi-objective optimization of the overlap,gap,deflection angle,and bending angle of the flap under takeoff and landing configurations is studied.The opti mization results show that under takeoff configuration,the variable camber trailing-edge flap can increase lift coefficient by about 8％ and lift-to-drag ratio by about 7％ compared with the traditional flap at a takeoff angle of 8°.Under landing configuration,the flap can improve the lift coef ficient at a stall angle of attack about 1.3％.Under cruise state,the flap helps to improve the lift-todrag ratio over a wide range of lift coefficients,and the maximum increment is about 30％.Finally,a corrugated structure-eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam.