Cloud Cavitating Flow Over a Submerged Axisymmetric Projectile and Comparison Between Two Dimensional RANS and Three Dimensional Large Eddy Simulation Methods

Abstract

For the cloud cavitation around slender axisymmetric projectiles, a twodimensional (2D) numerical method was based on the mixture approach with Singhal cavitation model and modified renormalizationgroup (RNG) k–خµ turbulence model, and a threedimensional (3D) method was established with largeeddy simulation (LES) and volume of fraction (VOF) approach. The commercial computational fluid dynamic (CFD) software fluent is used for the 2D simulation, and the open source code OpenFOAM is adopted for the 3D calculation. Experimental and numerical results were presented on a typical case, in which the projectile moves with a quasiconstant axial speed. Simulation results agree well with experimental results. An analysis of the evolution of cavitating flow was performed, and the related physical mechanism was discussed. Results demonstrate that shedding cavity collapse plays an important role in the generation and acceleration of reentry jet, which is the main reason for the instability of cloud cavitation. The 2D ReynoldsAveraged Navier–Stokes (RANS) method can represent the physical phenomena effectively. The 3D LES method can give an efficient simulation on the shedding vortices, and considerable accurate shapes of shedding cavities are captured.