Effect of probe support wake on vibration characteristics of compressor rotor blade

In order to understand the abnormal phenomenon of sudden increase of the vibration strain of the first rotor blade in an axial flow compressor experiment, the comparison experiment of the effects of different kinds of inlet measurement probes on vibration characteristics of the rotor blades was conducted. By comparing the variation of the rotor blade vibration signals under different installation layouts of inlet measurement probes, it is verified that the abnormal vibration of the rotor blade is caused by the inlet measurement probes. The flow mechanism of the probe support wake inducing the resonance of rotor blade was also analyzed using the fluid-structure coupling numerical simulation method. The investigation results show that the first order resonance of the rotor blade of the axial flow compressor emerges under an engine order excitation condition, which is induced by the cylindrical probe support with the diameter of 10 mm. As the size of the probe support decreases, the level of the rotor blade vibration response is reduced evidently. The disturbance frequency of the probe-support-induced-compressor-rotor-blade-resonance originates from the combined effect of the wake induction frequency and the passing frequency of the probe support. The shedding vortex of the probe support wake can cause large amplitude fluctuation of the inlet attack angle of the rotor blade.