Numerical and theoretical investigation of the high-speed compressible supercavitating flows

The objective of this paper is to investigate the high-speed compressible supercavitating flows with numerical and theoretical methods. In the numerical simulation, calculations are performed by solving the Unsteady Reynolds-averaged Navier-Stokes (URANS) Equations using a cell-centered finite-volume method, and the k-ω SST turbulence model is applied as the closure model. Compressibility effects in liquid phase are modified by the equation of state (EOS), and vapor phase is treated as ideal gas. Firstly, the numerical results are validated with experiments conducted by Hrubes (2001). Results are shown for high-subsonic and transonic projectiles, there is a general agreement between the predicted cavity profiles and the experimental data. Secondly, the influence of the Mach number on the flow structure and cavitation dynamics from subsonic to supersonic flows is investigated. The results show that with the increase of Mach number, the radial dimension of the front cavity is reduced, which is caused by the dramatic increase of pressure around the projectile. An expression is proposed to analyze the flow parameters before and behind the shock wave based on the isentropic and potential assumption at the Mach number on the interval 1 ≤ Ma≤2.2. The relationship between pressure and density across the shock wave is also investigated. Overall, these findings are great interest in engineering applications.