Flapping performance and simulation of an insect-mimicking flapper actuated by a compressed unimorph piezoelectric composite actuator

We have analyzed and experimentally examined the flapping performances in terms of aerodynamic force generation, flapping frequency and flapping angle of the two flappers actuated by the original LIPCA and the compressed LIPCA, respectively. The flapping tests for two wing shapes were conducted at three different wing rotation angles and various flapping frequencies to search for the optimum flapping frequency, at which the maximum aerodynamic force was achieved, and investigate the effect of wing shape and wing rotation angle on the force generation of the flapper. The aerodynamic forces were calculated by subtracting the inertia forces measured in the vacuum from the total forces measured in the air. For the CFD simulation, we established the corresponding kinematical equations of the wing by examining the high-speed camera images taken from front and top at the same time. The experimental results showed we could improve the flapping angle 18.2 % and the average vertical aerodynamic force 24.5 % by using the compressed LIPCA.