Cavitation
Cavitation is a phenomenon of liquid boiling and evaporation in an area where fluid pressure drops below the saturated vapor pressure. Flow pattern also changes when this occurs and in turn affects the performance of fluid machineries.
The air bubbles also formed in the process flow to the high-pressure region, pressure is increased, and the air bubbles collapse. The collapse causes noise and erosion on the surface of solid making it critical to predict the cavitation behavior accurately.
Cavitation at propeller under water
Having generally said that a very fine mesh is needed to accurately calculate the gas-liquid interfaces, The homogeneous model employed in scFLOW serves to effectively calculate the mixing ratio at the interface. The animation shows the occurrence of cavitation at the top surface of a propeller. Pressure at the surface is found dropped (isosurface of void fraction 0.1).
Cavitation in a mixed flow pump impeller
Cavitation often occurs in fluid machineries such as pumps, water turbines, and screw propellers all of which have an impeller to rotate at high speed. Computational modeling is an efficient tool in predicting erosions and performance losses due to cavitation, and even more, preventing cavitation itself. The animation shows a cavitation occurring particularly at the inlet of the impeller.