Abstract: Acoustic resonance is an important factor leading to blade fatigue for centrifugal compressor. But the investigation is limited in this area. It is especially without effective experimental testing to verify it. To investigate on the effect of acoustic resonance, LMS Virtual.Lab Acoustics simulation software is used to determine the acoustic modes based on the acoustic cavity of centrifugal compressor. Its acoustic modes frequency and modes of pressure distribution can be obtained. Fluid excitation frequency can be different by adjusting blade passing frequency. Acoustic resonance will happen when the blade passing frequency is close to acoustic mode. Model level testing rig of centrifugal compressor is used to verify the simulation analysis. Pressure pulsation of acoustic cavity is monitored. The frequency amplitudes for different blade passing frequency are determined. The pressure pulsation will be up to several times when the acoustic resonance occurs according to experiment analysis. It will lead to serious damage for the centrifugal compressor. This research verifies the pressure pulsation increasing for compressor as acoustic resonance. It can contribute to blade condition monitoring and the prohibition failure of centrifugal compressor.

Key words: centrifugal compressor;blade damage;acoustic modes;acoustic resonance