A Study of Aerodynamic Excitation Forces on a Radial Turbine Blade Due to Rotor-Stator Interaction

摘要

It is important to predict the resonant vibration level for the design of a variable nozzle turbine. In this study, unsteady CFD analyses are conducted to investigate the flow mechanism that causes aerodynamic excitation forces. As a result, it was found that excitation forces are affected by shock waves and the nozzle clearance flow, and that these forces could be modeled by using one-dimensional aerodynamic parameters for the impeller inlet's dynamic pressure and Mach number. Furthermore, the resonant vibration level was calculated by conducting CFD and FEM analyses and then comparing the results with the experimental data. As a result, it has been confirmed that the CFD results can be used for qualitative evaluations of excitation forces.