Rotating stalls in centrifugal impeller/vaned diffuser systems. 2nd report, Comparison between experiment and theory.

Rotating stalls in a centrifugal impeller/vaned diffuser system were studied experimentally and analytically. In this report, the diffuser vane angle and the number of vanes are changed and it is shown that the impeller-diffuser interaction effects on rotating stalls are qualitatively unchanged by those parameters. Simple expressions of the results of 2D stability analysis are given for the cases of isolated impeller, impeller/vaned diffuser combination, vaned and vaneless diffusers. Comparison with the experimental results shows that the models can be used for the identification of principal origin of various rotating stalls observed.