Numerical simulations of cavitating water jet by an improved cavitation model of compressible mixture flow with an emphasis on phase change effects

What is it about?

Cavitation is a complex phenomenon often encountered in engineering. This paper provides a practical way for treating high-speed cavitating flow by presenting an improved cavitation model of compressible mixture flow with an emphasis on phase change effects. The model is embedded in an unsteady Reynolds-averaged Navier–Stokes solver, with the realizable k- model employed to evaluate the eddy viscosity. The unsteady behavior of an impulsively started submerged water jet is investigated. The results reveal that cavitation occurs when p_in/P_in reaches 0.65 and fluid flow begins to pulsate. In the well-developed stage, one pair of ring-like clouds consisting of a leading cloud and a subsequent cloud is successively shed downstream, and this process is periodically repeated. The leading cloud is principally split by shear flow, and the subsequent cloud is detached by the re-entrant jet generated while a fully extended cavity breaks up. The subsequent cavitation cloud catches the leading one and they coalesce over the range x/d≈2~3. The mass flow rate coefficient pulsates from 0.59~0.66 corresponding to the periodic shedding of cavitation clouds.

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Photo by Ezra Jeffrey-Comeau on Unsplash

Photo by Ezra Jeffrey-Comeau on Unsplash