Analysis of Impeller Vibration in Radial Compressors
The prediction of the dynamic behaviour of the impellers is of considerable importance in the design of turbomachines. The excitation possibilities of the radial impellers by the forces or imposed displacements are various and an appreciation of the life of radial impellers is strongly bounded to an accurate dynamic analysis. Therefore, it is necessary to analyze them in order to improve the geometry or modify the design. In order to better understand and explain the dynamic behaviour of impellers, a series of impeller models with various numbers of blades of radial or tangential extention have been examined. Because of complexity of analytical analysis shown in earlier works, the eigenfrequencies and modes of the impellers were evaluated using a Finite Element program. Interferometric holography served as a means to visualize the dynamic behaviour of the impellers. An experimental modal analysis was used to identify the modal parameters. A detailed application of these methods to an actual centrifugal impeller was also reported along with theoretical and experimental investigations on the impeller models.