In today's post we will talk about cavitation. First of all, we have to talk about the concept of "vapor pressure". Vapor pressure is the pressure at which the liquid turns to vapor. This fluid property is directly related to the fluid temperature, that is, if we have a liquid with a higher pressure, we will have a higher evaporation temperature for it. In a fluid flow, there is always a decrease in pressure along the pipe and when the pressure reaches the vapor pressure, we will see bubbles of steam in it, in another words, the liquid will be transforming in a steam. However, at the pump, the pressure will be higher again, above of the vapor pressure, and the steam bubbles will implode. These implosions are so violent that they remove materials from the impeller and the casing of the pump. That phenomena is called "Cavitation". In the movie you can see the bubles inside the pump. In future post we will talk about the main effects of cavitation and how do you avoid it?
Written by Micelli Camargo - Mechanical Engineer and Creator of Engenharia e Cia Channel