Paper No. 25
D. R. Smith/J. C. Wachel, Turbomachinery International Magazine, January/February Ed., 1983, pp. 21-24 .
Flow instabilities in centrifugal compressors can produce low frequency turbulence and pulsations which can result in nonsynchronous rotor vibrations, vibrations of the case and attached piping, speed modulations, and reduced compressor performance. High frequency pulsation in rotating equipment typically occur at multiples of running speed such as blade, diffuser and nozzle passing frequencies and can excite blade natural frequencies and radial shell wall resonances. The piping lateral mechanical and acoustical natural frequencies are generally at lower frequencies and are not excited by these pulsations.