Measured pressure pulses vs PumpLinx predictions for a pump cavitating at altitude
The Simerics Cavitation Module includes three compressible effects: 1) The bulk modulus of the pure liquid, 2) the compressible effects of any vapor (due to cavitation) and 3) the compressible effects of any Non-Condensable Gas (e.g. air) in the liquid. This enables the Cavitation Module to accurately model pressure waves generated and propagated through a system.
The example shown above is for an aircraft pump. At higher altitudes, the pump cavitated due to the lower inlet pressure, as shown in the pressure measurements on the left, taken at the pump outlet. The plot on the right is the predicted pressure ripple as predicted by PumpLinx using the Cavitation Module. The close correlation of the predicted magnitude and frequency of the cavitation induced pressure pulses/noise, enabled the client to analyze design improvements to reduce the noise.
This is what a major US automobile manufacturer had to say about the ability of PumpLinx regarding predicting noise:
“PumpLinx is enabling the automotive industry to reduce the noise emissions for their automobile oil pumps. Our designers were able to reduce the noise for a production line oil pump by over 30 decibels. That is similar to dropping from normal conversation down to a whisper, and, after all, who wants their car oil pump talking above a whisper? This dramatic reduction was accomplished by using PumpLinx to identify the source of pressure ripples causing unnecessary noise. Once the sources were identify, our design engineers were able to eliminate the cause and silence the chatter. The result is a quieter, more efficient pump.”