Numerical Simulation of High-Speed Cavitating Water-Jet Issuing From a Submerged Nozzle

Abstract

A simplified estimation for the compressibility of cavitating flow is proposed based on the bubble cavitation model and a compressible mixture flow method is developed for the numerical simulation of high-speed cavitating jet by coupling the simplified estimation of bubble cavitation to a compressible turbulent flow computation procedure. The intensity of cavitation in a local field is evaluated by the volume fraction of gas phase, which is governed by the compressibility of bubble-liquid mixture at the current status of local flow field. The method is applied to the simulation of high-speed submerged water jets issuing from an orifice nozzle. Both non-cavitating and cavitating jets are calculated under different cavitation numbers in order to clarify the cavitation property of submerged water jet. The results demonstrate that the intensity of cavitation denoted by the maximum value of gas volume fraction and the area of strong cavitation indicted by high value of gas volume fraction increase with the decrease of cavitation number. Under the effect of cavitation bubbles the discharge coefficient of orifice nozzle decreases with the cavitation number.