Design and Characterization of a Centrifugal Compressor Surge Test Rig

Figure 11

Pressure fluctuations in the inlet during the onset of surge at 16,000 rpm: (A) instability initiation—observed audible sound change, (B) initial pressure fluctuations at a frequency near 21 Hz, and (C) pressure fluctuations changed to a lower frequency near 7 Hz as throttle valve closed further.