Prediction method of resonant response of rotor blades considering multi-row effects on aerodynamic damping

This study investigates the forced vibration response of a two-row model of an Inlet Guide Vane (IGV) and rotor at resonance speed through numerical simulations. A resonant response prediction method based on equivalent damping balance has been validated, which ensures computational accuracy while reducing response calculation time to only 1% of the traditional transient response method. At resonance speed, unsteady pressure disturbances on the rotor blade surface mainly arise from two sources: IGV wakes and blade vibrations. The unsteady pressure caused by the IGV wakes provides excitation for the system, while the unsteady pressure caused by rotor blade vibrations provides damping. By studying the characteristics of unsteady pressure caused by IGV wakes and vibrations at resonance speed, a method for separating unsteady pressure caused by stator wakes and vibrations has been presented, accurately obtaining aerodynamic damping under multi-row resonance conditions. Compared to the aerodynamic damping obtained from multi-row scenarios without separating unsteady pressures caused by stator wakes and vibrations, and the traditional isolated blade row scheme, the aerodynamic damping considering the effects of multi-row and IGV wakes at resonance speed is smaller. Based on the separated unsteady pressures caused by IGV wakes and vibrations, and combined with the equivalent damping balance method for predicting forced response, a forced response analysis method considering both flow field disturbance excitation and damping effects has been established.