Comparative Analysis of Rotordynamic Force Prediction for a Shrouded Impeller Based on CFD Geometry Modeling Scope

This study investigates how geometric boundary scope affects fluid-induced rotordynamics force prediction in shrouded centrifugal impellers using CFD. Three models (referred to in this study as ‘simple’, ‘without an impeller’ and ‘with an impeller’) are analyzed under eccentric whirling motion. Results demonstrate that a simplified model, when properly calibrated, yields rotordynamic coefficients comparable to those of the full model. The simplified approach reduces computational time by approximately 66% while still ensuring reliable prediction accuracy; therefore, it can be considered an efficient method for predicting rotordynamics force.