Abstract
The flow field during rotating stall in a radial vaneless diffuser was investigated experimentally using PIV. Experiments were conducted in a radial vaneless diffuser of an open loop centrifugal blower. Although PIV offers high spatial resolution, it is inadequate measuring method for the flow with large velocity fluctuation such as inside the turbo machinery because of its low resolution in time domain. During the experiments static pressure and instants of the frame acquisition were also recorded. Unsynchronized relation between the time instant of the frame acquisition and the pressure signal allowed to measure different phases of periodic phenomena. And the velocity data was reordered in the postprocessing procedure. As result, the velocity field of the diffuser during rotating stall is clarified precisely.
