Flapping-Wing Propulsion for a Micro Air Vehicle

Recent interest in the development of micro-airvehicles (MAVs) has led to a renewed interest in apping-wing propulsion due to the relatively poor e ciencies of conventional propellers at these small scales. In the present study apping-wing con gurations found numerically to produce high propulsive-e ciencies are investigated experimentally. Several models of varying scales and complexity are developed and tested in a low-speed wind-tunnel. The variation in scale of the models provides some insight into the rather severe Reynolds number e ects, and the development of the smaller models provides an introduction into the di culties in the design, manufacture and testing of small-scale vehicles. The thrust is measured directly and compared with numerical predictions, with variations in the apping motion, aspect-ratio and scale. Measured thrust for the larger model compares well with the numerical predictions both qualitatively and quantitatively over most of the parameter-space, however, the smaller model, with approximately half the chord-length and a somewhat di erent apping motion, produces drastically di erent performance, indicating the presence of massive ow separation. The presented results indicate the necessity to better understand, and ultimately to utilize, ow separation in the design of successful apping-wing MAVs.