The Characteristics and Mechanisms of High-Intensity Sound in a High-Speed Multistage Compressor

An experiment with a multistage high-speed compressor is conducted to investigate the high noise with abnormal blade vibration. Different points are selected to monitor the noise in the compressor and the amplitude of blade vibration. The evolution rhythm of sound frequency and sound pressure level against speed is captured. The relation between the vibration and the noise is obtained. A research method based on an acoustic analogy is developed to investigate the characteristics and mechanisms of high-intensity sound in a rectangular cavity pipeline. The calculated distribution of the first four-order acoustic mode inside the rectangular cavity pipe is consistent with the results in the literature, and the maximum calculation error of the acoustic mode frequency value is 2.7%, which certifies the effectiveness of the method. A simplified compressor model is established to study the vortex system and the sound field characteristics of this method when high-intensity sound occurs. The results present the motion law of shedding vortices with high-intensity sound, and the calculation error of the frequency corresponding to the high-intensity sound is 3.6%. The "frequency-locked phase-locked" characteristics (i.e., character frequency) keep constant at a range of velocities, showing similarity with the phenomenon obtained in experiment above, and beta mode forms of Parker are captured. The study in the present paper makes a contribution for the cognition of mechanisms with high-intensity sound in aeroengine compressors.