Numerical simulations of cavitating turbulent flow around a marine propeller behind the hull with analyses of the vorticity distribution and particle tracks

摘要

The k-omega SST turbulence model was coupled with a homogenous cavitation model to simulate cavitating turbulent flow around a highly-skewed propeller behind a ship hull. The influence of the mesh resolution was investigated by an uncertainty analysis and comparisons with experimental data. The main contribution in this paper is to study the cavitating flow around the propeller behind the hull by the relative vorticity transport equation and particle trajectories. The results show that the present method can accurately simulate the transient cavitating flow around a marine propeller behind a hull. The predicted thrust coefficients, cavitation patterns and pressure fluctuations agree well with experimental data. Furthermore, the relative vorticity transport equation was used to analyze the cavitation influence on the vorticity transport. These results show that the leading edge vortex, mass transfer across the liquid-vapor interface and the side-entrant jet significantly influence the relative vorticity distribution. Moreover, particle trajectories were predicted using a three-dimensional Lagrangian technology to study the local cavitating flow structure from the Lagrangian viewpoint. The particle tracks demonstrate that the propeller rotation and the twisted geometry lead to a much more complex, distorted flow structures.