Some aspects of cavitation phenomena in centrifugal pumps

Abstract

The work reported in this thesis has a fourfold objective, namely, to study:

The influence of Froude number on the inception of cavitation in radial flow pumps. The influence of prerotation on the cavitation performance of radial flow pumps. The influence of temperature on cavitation inception in radial flow pumps, and Cavitation phenomenon visually.

The thesis has been divided into two chapters. The first deals with the motivation for the work reported herein and gives a review of the published literature of immediate interest to the work. The second chapter describes the design of the test rig, the experimental equipment used, and gives the results of the experiments. An analysis of the experimental results leads to the conclusions that:

The critical sigma for a pump varies slowly at high Froude numbers and exhibits a minimum and a maximum at lower Froude numbers. Positive prerotation induced in the suction pipe has a marginal effect on the cavitation performance. The break-off sigma has a minimum value at a water temperature between 40°C and 50°C. The effect of temperature, however, is a complex one.

Photographs showing cavitation in the pump at different operating conditions are presented.