Practical Solutions to Machinery and Maintenance Vibration Problems
Chapter 9, Fluid Flow
Section 4, Summary
The following highlights should be considered when analyzing fluid-related vibration problems:
a) Cavitation does not usually show vanepass frequency and is highest on the suction side. The amplitude of the broadband-wide frequency vibration rarely exceeds alert values. Resonance peaks associated with this problem are normally not related to rotational frequencies.
b) Recirculation does usually show vanepass frequency and is strongest on the discharge side. The amplitudes often exceed alert values especially when resonance is involved. The random broadband vibration occurs in the lower frequency ranges.
c) Turbulence usually shows as low amplitude, low frequency range broadband noise with the dominant peaks at sub-rotational frequencies.
d) As with all other vibration problems, history is of paramount importance. Whether the vibrating has been apparent since new or whether it only appears under certain operating conditions, it is information that can be vital to a successful analysis.
e) Analysis tips:
This textbook contains only part of the information in our Practical Solutions seminar.