The CFD driven optimisation of a modified venturi for cavitational activity

Abstract

This work presents CFD-based optimisation of the important geometrical parameters of a cavitating venturi. The parameters for optimisation were selected based on the analysis of the steps involved in the cavitation process like cavity inception, cavity growth, and cavity collapse. It was seen that the ratio of the perimeter of the venturi to the cross-sectional area of its constriction quantifies the possible location of the inception of the cavity. The ratio of the throat length to its height (in the case of a slit venturi) controls the maximum size of the cavity and the angle of the divergence section controls the rate of collapse of a cavity. Based on the numerical study, it was concluded that a slit venturi (α=2.7) with the slit length equal to its height (1:1) and a half angle of divergence section of 5.5' is an optimum geometry for best cavitational activity.