VIBRATION CHARACTERISTICS ANALYSIS OF THE ROTATING BLADE BASED ON AN POLYNOMIAL AERODYNAMIC FORCE

摘要

In this paper, aerodynamic expressions in forms of the series and the polynomial for a blade with low speed in low pressure compressor are deduced by numerical simulation. Considering shear deformation and cross-section warping effect, the blade is simplified as a pre-twist, pre-setting rotating cantilever plate, which subjected to the aerodynamic force and the centrifugal force. Based on the first-order shear deformation theory and von-Karman nonlinear geometric relationship, nonlinear partial differential dynamic equation of the rotating blade is derived by using Hamilton principle. Equations of motion are converted into a series of ordinary differential equations using Galerkin method. The dynamic frequency and the dynamic deformation of the blade are explored and contrasted with results obtained by finite element method. Effects of parameters on vibration characteristics of the blade under different rotation speed are analyzed. Results show that the explicit expression of the aerodynamic force for the blade has a good applicability.