Research on parameters influencing flutter characteristics of transonic fan blade

Three-dimensional Reynolds averaged Navier-Stokes equations are solved based on the harmonic balance method in frequency domain in order to numerically simulate unsteady flow around an oscillating blade, and the energy method is applied to calculate the aerodynamic damping coefficients in the one-way fluid-structure manner. The flutter characteristics of a transonic fan are predicted at design operation and near stall working point for 100% rotation speed line respectively. The flutter mechanisms is revealed by investigating the influence of Inter-Blade Phase Angle (IBPA), blade modes, shock wave and incidence flow angle on aeroelastic stability. The numerical results indicate that the unsteady shock wave disturbance on the pressure surface is a main inducement of aeroelastic instability and the other physical parameters have also varying degree of impact on the flutter characteristic.