Opening adress by the Chairman
1983, Zeszyt 83-84
Abstract
Results of cavitation investigations of a diagonal pump are presented. The investigations included observations of the size and shape of cavitation cloud in the impeller, influence of cavitation on the energy exchange between the liquid and the blading, intensity of destructive effect of the phenomena and associated noise and pressure pulsation.
It could be concluded on the basis of the above results that three aspects of cavitation in a hydraulic machine should be taken into account in order to fully chatacterize its course. These are spatial dimensions and position, disturbances of head/discharge curves, and the influence on the working part of erosion and vibrations of the system. The relation between the appearance of the respective aspects and between their intensities is not defined strictly. Possibiiities of concluding on some aspects based on the data on the intensity of one of the others are very limited. It is also impossible to quantitatively evaluate some aspects on the basis of measuremęnts of the oihers. Besides, the dependence between intensities of the respective aspects is an individual feature of the machine type.
Results of diagnostics of cavitation characteristics carried out using most popular indirect methods are presented. It was concluded that each of indirect diagnostic methods concefns sone cavitation aspects only. Besides, the relation obtained has a qualitative character only.
Keywords:
cavitation, diagonal pump, cavitation cloud, impeller, influence, energy exchange, spatial dimensions