Cavitation in hydraulic machinery

The phenomenon of cavitation can be revealed, among others, in technics by decreased efficiency of machinery and installations, in medicine by negative action on heart and circulatory system, in biology by disintegration of erythrocytes and bacteria. Cavitation penetrates each year deeper and deeper to many regions of technics, chemistry, biology and medicine. Cavotation as the process of formation of fluid discontinuity under negative pressures is a very complex phenomenon and depends on fluid parameters and its motion. For the time being no consistent theory of the cavitation phenomenon was produced that would include all fluid properties. Several simple cases were only analyzed. The results of that analysis give a flavour of cavitation phenomenon, sufficient enough to make preliminary considerations of the influence of basic factors (pressure, temperature, velocity) on the course of that phenomenon. The change of the motion character, caused by cavitation, results in the change in pressure distribution of the whole flow area and in such away affects the phenomenon itself. In this paper individual phases of that phenomenon are examined: a) initial phase of cavitation formation; b) phase of developing cavitation, and c) phase of fully developed cavitation.