356 ケーシング形状がインデューサの内部流動に与える影響(G05-7 流体機械(2),G05 流体工学)  [in Japanese] 356 Effect of the Casing Configuration on Internal Flow in an Inducer  [in Japanese]

In order to investigate the suppression of rotating cavitation, it experimented by using PIV visualization and two configurations of the casing. One is a straight casing (without step) where rotating cavitation occurred easily and the other is a step casing where rotating cavitation was able to be controlled. As results, axial direction velocity u/u_t at x-θ_<0-120°> section indicated wide back flow region with the step casing. In addition, large positive vorticity (anti-clock wise) region was observed in front of the inducer with the step casing. It was that the wide tip clearance at the step casing inlet contributes growth suppression effect of the rotating cavitation.