Research on the Turbine Blade Vibration Base on the Immersed Boundary Method

Abstract

This paper is concerned with the study of a kind of discrete forcing immersed boundary method (IBM) by which the loosely aero-elasticity coupled method is developed to analyze turbine blade vibration. In order to reduce the spurious oscillations at steep gradients in the compressible viscous flowing field, a five orders weighted essentially nonoscillatory scheme (WENO) is introduced into the flow solver based on large eddy simulation (LES). The three-dimensional (3D) full-annulus domain of the last two stages of an industrial steam axial turbine is adopted to validate the developed method. By the method, the process of grid generation becomes very simple and the unsteady data transferring between stator and rotor is realized without the process of being averaged or weighted. Based on the analysis of some important aerodynamic parameters, it is believed that hypothesis of azimuthal periodicity is not reasonable in this case and full-annulus passages model is more feasible and suitable to the research of turbine blade vibration. Meanwhile, the blade vibration data are also discussed. It is at about 65% of rotor blade height of the last stage that an inflection point is observed and the midspan region of the blade is the vulnerable part damaged potentially by the blade vibration.