APPLICATION OF NON-LINEAR TURBULENCE MODELS ON THE NUMERICAL SIMULATION OF CAVITATING FLOWS

摘要

Quadratic and cubic non-linear eddy-viscosity turbulence Models (NLEVM) with low Reynolds number correction were employed to provide better treatment about the anisotropic turbulence stresses in cavitating flows, in which large density ratio and swirling structures consist. These models were carried out through a self-developed computer code, and were validated by the case of the cavity over disk cavitator. It was proven that, the nonlinear models could effectively eliminate the non-physical numerical oscillation of the cavity profile which was usually caused by linear models. It had also been experimentally proved that the computed cavity shapes and pressure inside the cavity were accurately captured by these nonlinear models. One of such nonlinear models was further applied on the simulation of the cavitating flows around submerged vehicles. The numerical results were compared with experiment data to investigate the influence of the vehicle's head and the after-body on the characteristics of the cavity. Ultimately, the cavitating flows around an especially designed complex underwater vehicle were predicted using the cubic k-ε turbulence model. The corresponding cavitation behaviors were studied to provide a beneficial experience for the research in future.