Combined Flow and Shape Measurements of the Flapping Flight of Freely Flying Barn Owls

Abstract

The underlying physics of the flight of birds is still not fully understood, in part due to the very complex wing movement and a lack of appropriate measurement techniques. Modern measurement technologies for fluid flows are often not suited for experiments with living animals, since these techniques may potentially harm the animal (e.g. lasers). The objective of this project was to modify the established technology Particle Image Velocimetry (PIV) to measure the flow around trained barn owls with the least possible hazard to the health of the animals. Furthermore, the shape of the wings was measured simultaneously using Projected Pattern Correlation Technique (PROPAC) to correlate the flow with the shape and movement of the wings. Results of the measurements of gliding and flapping flight are presented in this chapter.