An exact analysis of cavitating flows in a centrifugal pump eludes engineers. A simplifying concept of notional spherical cavities is proposed which, it is suggested, has sufficient validity to be a very useful tool in predicting some aspects of volumetric performance. A method of applying an analysis based on this concept is given.
The volumetric performance predicted for different pumped liquid properties or a different pump speed from data obtained in a single reference test are: (i) the value of nett positive suction head (NPSH) at generated head breakdown; (ii) the generated head/cavitation zone length curve.
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