Flow Field and Vibration Behavior of the Rotor due to Mistuning IGV in a Transonic Compressor

A fluid-structure coupled approach is utilized to study the influence of mistuning IGV blade on rotor flow field and blade vibration behavior of a transonic compressor. Interaction between fluid and structure are dealt with in a coupled manner, based on the interface exchange of information between the aerodynamic and structural model. The computation fluid mesh is updated at every time step with an improved algebraic method. The unsteady flow field of IGV/rotor with one mistuned IGV blade is studied using full-annulus, 3D CFD model. Then a reduced half-annulus CFD model with one mistuned IGV blade coupled with rotor FEA model is used to identify model shapes, frequencies, vibration stress and the structural deformations. The results show that the mistuning IGV cause the performance map of rotor shift towards the lower flow rate from the rotor with normal IGV. A significant low-frequency and its multiple pressure fluctuation appear in mistuning IGV wake, the fundamental frequency of IGV wake is closely related with the number of mistuning blade. Compared with normal IGV model, the vibration characteristics of rotor blade changed, blade vibration frequency is the same as the main frequency of mistuning IGV wake.