Investigation of numerical models of cavitation phenomenon in its prediction in nozzles

Abstract

Cavitation is a phenomenon during which, with the movement of the flow and the reduction of the liquid pressure to the saturated vapor pressure of the liquid in susceptible areas, bubbles of air are formed during the flow. The microjet becomes full of energy with the fluid, which when these micro jets collide with the walls, causing vibration and noise and destructive effects such as structural erosion of ship propellers, pump blades, and dams, as well as reducing efficiency, and malfunction of hydraulic devices. This research aims to study different simulation models of the cavitation phenomenon and compare them in the way of cavitation cloud creation and expansion and the effect of this phenomenon on the flow. The present research has been analyzed numerically using ANSYS FLUENT software. In this research, an attempt has been made to study and compare different cavitation models in various geometries. Also, in one example, the results of the numerical model have been compared with the results of the laboratory model. The results showed that the formation of cavitation phenomenon in 10 cm throat compared to 5 cm by 5.88%, in 10 cm throat compared to without throat by 64.71%, and in 5 cm throat compared to without throat by 5.62% has changed.

Keywords

• cavitation
• two-phase flow
• computational fluid dynamics
• saturated vapor pressure