Numerical study of the cavitating flow over backward facing step with a polydisperse two-phase flow model

We study the cavitating flow over a backward facing step with an incompressible polydisperse cavitation model. The model can predict experimental observations for this reasonably well, including shedding cloud characterized by condensation front, cavity length, void fraction, and frequency. All variations produced cavities, but turbulence grid resolution are essential better predictions, delayed detached eddy simulation (DDES) performing than Reynolds-averaged Navier–Stokes. Quantities, such as pressures at key points, maximum fraction location, frequency, mildly sensitive to those factors. Finer DDES resolution, crucial resolve small vortices where occurs in their low pressure cores, improves predictions. Since fully produces front that follows well trends, it is concluded compressibility not necessary condition formation of front. Consequently, speed sound mixture does appear play important role evolution. nature allows prediction bubble size distribution. Small bubbles concentrate on downstream section cavity, collapse strongest fission most intense, while larger reside near milder. moving source vorticity liquid phase “compressibility,” sense density changes due changes, baroclinic effects significant, buoyancy effect negligible.