Compressor Three-dimensional Unsteady Flow Calculation And Blade Forced Response Study

Through solving the Navier-Stokes equation, three dimensional transonic unsteady flow in isolated rotor blade was simulated. The non-oscillatory, no free parameters, dissipative and high-resolution NND scheme was adopted for spatial discretization. In order to reduce the calculating time, Dual-time stepping method was employed. In the pseudo- time region, high efficient LU-SGS scheme was used in time-marching.Cases with uniform or non-uniform inlet stagnation pressure and with or without tip-gap flow were studied. Computed results showed that complex structure vortex appeared and secondary flow occurred in the flow of cascade with tip-gap. These phenomena are roots of the unsteady excitation.ANSYS was used to solve the structure dynamic equations to obtain the natural frequency of vibration and mode shape of the blade. Coupled with the simulation of unsteady flow, the resonance analysis was studied.As an application, the dynamic stress of the blade was analysed with ANSYS based on the computation of unsteady flow. The result may be useful in the engineering practice.