Application of PIV techniques for rotor blade tip vortex characterization

Abstract

To investigate the development of blade tip vortices under different rotor conditions like thrust and rotational speed, both 2C and 3C PIV measurements were performed on a 40% Mach scaled Bo105 model rotor in hover condition. The vortices were traced from the trailing edge of the blade up to half a revolution behind the blade with azimuth steps between 1° to 10° and different spatial resolutions. In addition, a sequence of three-component measurements was performed just after the vortex creation at finer azimuth steps of 0.056° to generate a 3D volumetric data set of the blade tip vortex. The influence of the PIV image analysis parameters on the vortex parameters derived - in particular sampling window size and window overlap - has been investigated. The measurements presented are part of the HOTIS (HOver TIp vortex Structure) project.