Multi-stereo PIV measurement of propeller wake flow in industrial facility

Kurzfassung

The flow in the wake of an 11-bladed propeller is investigated by means of phase-locked multi-stereo Particle Image Velocimetry. The use of multiple stereo-PIV systems and the multi-pulse acquisition strategy allow for the reduction of the measurement error and for the enhancement of the velocity dynamic range. The application of the measurement technique in the Airbus Low Speed Wind Tunnel industrial facility (LSWT, Bremen, Germany) poses challenges mainly due to the vibrations of the imaging system and acquisition phase jitter, ultimately affecting the spatial resolution of the measurement. A correction scheme based on the analysis of velocity fields from different stereo-PIV systems is used to largely compensate these effects, providing velocity fields suitable to be used for validation of computational aeroacoustics codes. Results show that a lower measurement error can be achieved when velocity fields from several stereo-PIV systems are combined. Furthermore, the correction scheme appears to reduce the signal modulation introduced by vibrations in the wake region.