Question

Write short notes on Cavitation in turbines .

Answer 1

Cavitation is defined as the process of formation of the vapor phase of a liquid when it is

subjected to reduced pressures at constant ambient temperature . Although other

factors such as changes in temperature, turbulence and velocity play a role, the change of

liquid to vapor is the same. When bubbles then enter a region of higher pressure or lower

temperature, they collapse violently producing a jet of liquid that creates shockwave

upon impact with a surface enough force to erode metal. Although the collapse is

generally a low-energy event, it is highly localized. The figure below illustrates the

collapsing phase and resulting jet, referred to as the re-entrant micro jet