The effects of the inlet casing configurations on unsteady cavitation were examined with a 3-bladed inducer. The inlet flow and cavitation pattern with two casings were visualized using by PIV and high-speed video. It was found that the rotating cavitation would be suppressed when the tip clearance at the inducer inlet was increased. The vortex cavitation in tip leakage flow and cavitation in back flow effected the suppression of the rotating cavitation through the inlet casing configuration.
