Numerical Investigation of Cavitating Flows in Different Shape Orifices

Cavitation is the formation and then immediate implosion of cavities in liquid –i.e. small liquid-free zones or bubbles – that are the consequence of forcesacting upon the liquid. It usually occurs when a liquid is subjected to rapid changes of pressure that cause the formation of cavities where the pressure is relativelylow. This paper examines cavitation in the pressuredriven flow of water through a sharp-edged orifice. This is a typical configuration in fuel injectors, andbrings a challenge to the physics and numerical of cavitation models, because of the high pressure differentials involved and the high ratio of liquid tovapor density. The multiphase capability of Ansys Fluent® can predict strong cavitation in flow separation regions [6]. Then the cavitation caused bythe flow separation after a ramped edged and curved edged orifices were examined. The flow is pressure driven, with inlet and outlet pressures defined. Thegeometrical parameters such as the orifice diameter, the inlet diameter and orifice length are definedcompletely. A steady-state solution is calculated to simulate the formation of vapor in the neck of the flow after the section restriction at the orifice.

Keywords:

Cavitation Modeling , Mixture Model , Ansys Fluent , Multiphase Modeling