APPLICATION OF THREE-COMPONENT PIV TO A HOVERING ROTOR WAKE

Three-component velocity measurements in the wake of a two-bladed rotor in hover were made using the Particle Image Velocimetry (PIV) technique. The velocity fields were oriented in a plane normal to the rotor disk and were acquired for wake ages ranging from 0 to 270 deg. for one rotor thrust condition. The experimental setup and processing of the instantaneous images are discussed. Data averaging schemes are demonstrated to mitigate the smearing effects of vortex wander. The effect of vortex wander on the measured vortex core size is presented.