Modeling and Dynamic Analysis of Shrouded Turbine Blades in Aero-Engines

Abstract

The impact vibration between shrouded turbine blades in an aero-engine is analyzed in this paper to study the influence of the parameters on the dynamic behavior. To investigate the impact vibration, a model composed of springs and a cantilever beam carrying a mass is developed to simulate the shrouded turbine blade in aero-engines. The Euler-Bernoulli beam theory is used in deriving the equation of motion and the associated boundary conditions. Employing the Galerkin method, an approximate solution is obtained by using the Fourier series method. Explicit expressions are obtained to calculate the responses and the mode shapes. Based on the expressions, parametric analysis is performed to study the effect of the stiffness ratio, the mass ratio and the gas amplitude of the excitation force on the steady-state responses of the system. The research work offers a calculating method for the quantitative optimization. Two types of the impact vibration that occur in the system are studied: the 1-side impact where only one side of the shroud collides with another shroud, and the 2-side impact where both sides of the shroud collide with the adjacent shrouds. Comparisons between the two types of the impact vibration show that the amplitude of the 1-side impact is larger than that of the 2-side impact while the resonance frequency of the 1-side impact is smaller.