Effect of camber on the aerodynamics of adaptive wing micro air vehicles

Four micro air vehicle wind tunnel models were built with 3, 6, 9 and 12% camber, all based upon the S5010-TOP24C-REF thin, cambered plate airfoil. These models were tested in the Low Speed Wind Tunnel at angles of attack ranging from 0 to 35° and velocities of 5, 7.5 and 10 m/s, corresponding to chord Reynolds numbers of 5x10⁴, 7.5x10⁴ and 1x10⁵, respectively. C_L, C_D, C_M and L/D were obtained and plotted versus angle of attack for all the cambers at each velocity. Large positive, nose-up pitching moment coefficients were found with all cambers at the lowest Reynolds number. These results have been verified with flight tests of micro air vehicles utilizing these airfoils. The 3% camber wing gives the best lift-to-drag ratio of the four cambers and theoretically would be the optimal choice for high speed, efficient flight. It is theorized that the 9% camber wing will give the best low-speed performance due to its high lift-to-drag ratio and mild pitching moment near its stall angle of attack.