Numerical study of cavitating flows around an immersed solid body.

A numerical approach is presented for cavitating flows around an immersed solid body. The single-fluid model for cavitating flows, which is based on a barotropic relation between fluid density and pressure variations in the liquid-vapor phase-change region, is coupled to a fictitious-domain (FD) method, where the immersed solid region is assumed to be filled with the surrounding fluid with a high viscosity. The FD method can be efficiently applied to complex body geometries without generating body-fitted meshes and does not need an explicit calculation of forces and toques acting on the solid boundary unlike immersed boundary methods. The conservation equations of mass and momentum with the compressibility effect in the cavitation region are solved by employing a projection method and a semi-implicit pressure correction method to avoid the serous time step restriction in weakly compressible flows. The present numerical method combined with a non-equilibrium k-$\varepsilon $ turbulence model is tested through computations of cavitating flows around a hemispherical body and a wedge-shaped body, whose numerical results or experimental data are available in the literature. The numerical method is extended for cavitating flows around a moving solid body.