Prediction of transonic flutter in oscillating cascades

摘要

A numerical simulation method of coupled CFD-CSD analysis in turbomachinery biddings, focusing on the influence of Interblade Phase Angle (IBPA) on aeroelastic stability, was developed. The node displacements of structural model, transferring to fluid interface nodes with finite element interpolation algorithm, are obtained on the basis of Computational Structural Dynamics (CSD). As for Computational Fluid Dynamics (CFD), Finite Volume Method (FVM) is used to solve Reynolds averaged Navier-Stokes (RANS) equations with k — ε turbulence models for closure. For NASA Rotor 67, the aerodynamic work done per oscillating cycle and the corresponding aerodynamic modal damping ratios at the first three modes of rotating blade has been computed to investigate the influence of mode shape on flutter. And the effects of IBPA on flutter have also been investigated by the validated numerical method. The aerodynamic modal damping ratios form the coupled CFD-CSD analysis is feasible to preliminarily predict blade's aeroelastic stability, which shows that mode shape and IBPA are the key contributors to flutter.