A Method for Rotordynamic Force Prediction of a Centrifugal Compressor Impeller Front Cavity Using a Transient Whirling CFD Technique

Abstract In order to improve the rotordynamic stability predictions of centrifugal compressor impeller front cavities, a method for modeling the eye seal and shroud cavity using transient, moving wall, CFD simulation is presented. This method allows for the extraction of the rotordynamic coefficients from the eye seal and impeller front cavity using a single model. This paper presents the details of the method as well as a set of typical results at various different whirling frequencies for a centrifugal impeller front cavity. Along with the CFD derived rotordynamic coefficients, predictions using correlations from the literature are also presented for comparison.