Deterministic interaction between inlet guide vanes and rotor blades in a centrifugal compressor

The deterministic interaction phenomenon between blade rows was investigated for a high speed and small mass flow centrifugal compressor with inlet guide vanes (IGV). The steady simulation was carried out firstly and the validity of simulation method was confirmed by comparing the simulation results with the experiment results. Then the unsteady simulation was carried out on the basis of steady simulation. The distribution forms of rotor spatial fluctuation, stator spatial fluctuation and pure unsteady fluctuation between blade rows were obtained by using the deterministic fluctuation decomposition method. The results showed that the pure unsteady fluctuation behaves as a double-peak, oscillating wave (positive-negative over time) that is centered on the pitch position of the time-average IGV wakes. It is also investigated that the IGV wake oscillation characteristic with the mass flow change, as shown that the oscillation magnitude is increased as the mass flow decreased. The spatial static pressure fluctuation of rotor blades occupies a dominant position on the total deterministic pressure fluctuation for deterministic unsteady static pressure components' fluctuation distribution between the IGV and rotor blades. This indicated that the unsteady pressure field is mainly caused by the rotor blade potential effect.