Experimental Flow Field Investigations for ‚MICRO AIR VEHICLES‘ in Flapping Motion

Abstract

Accompanying the growing interest in Micro Air Vehicles (MAV) over recent decades investigations for flapping flight of birds and insects have been increased. Although up until the present many basic phenomena have been explored and are understood, there are nevertheless still many unanswered questions. The present paper discusses first results of a measurement campaign for investigating flapping flight in more detail. The results presented refer to flow field measurements using Particle Image Velocimetry (PIV) applied in span-wise distributed planes on the upper side and wake of specially designed MAV models. The spatial flow topology and the interaction of vortex structures are shown. Special attention is paid to the differences between two types of motion: pure plunge and a combination of plunge and pitch motion. For the second type a strong reduction of the vortex structures is visible which is related to a reduction of the effective angle of attack.