Measurement of unsteady aerodynamic forces of 3D flapping wing in hovering flight (1st report, influences of Reynolds number, reduced frequency and planform)

An experimental study of the aerodynamic characteristics of 3-dimensional flapping wing in hovering flight is conducted in the wide range of parameters, which are Reynolds number, reduced frequency and wing planforms. Lift and power are measured on scaled flapping wings, which mimic bumblebee and cicada wings, and which are delta wings with different locations of maximum chord. The results show that lift and power (1) are almost unchanged in Re = 800 -5 000, (2) increase as the reduced frequency increases, although the effeciency is constant, and (3) increase as the location of maximum chord moves from wing base to tip, although the effeciency decreases.