Influence of Vaned Diffuser on Dangerous Blade Vibration due to Blade Flow Interactions in a Centrifugal Compressor

Influence of diffuser vane position on dangerous blade vibration due to blade flow interactions at part load operating condition was investigated in a centrifugal compressor. By means of some measurement and analysis techniques a mechanism of interaction between blade vibration and circumferential flow condition in the impeller with vaned diffuser was determined, which is a cause of dangerous blade vibration in resonance. Experiments for the compressor with different radial diffuser positions have been performed to reduce the effect of the blade flow interaction and the dangerous blade vibration A quantitative estimate of the influence of vaneless space length between diffuser and impeller on the blade flow interaction was made. An optimal diffuser position with lower blade vibration and higher compressor characteristics was determined.Copyright © 1995 by ASME