Effect of turbulence models on RANS computation of propeller vortex flow

The steady-state tip vortex flow of a David Taylor Model Basin (DTMB) propeller model has been computed using a RANS solver on a spiral-like structured grid with grid concentration aligned with the vortex core. Sensitivity of the numerical solutions to grid resolutions and distributions was studied. To investigate the effect of turbulence models on the predicted tip vortex flow and the open-water performance, a number of eddy viscosity turbulence models and Reynolds-stress models were used in combination with various grids. The computed velocities across the tip vortex core and their fluctuations at near field, the circumferentially averaged velocities outside the tip vortex region, and the thrust and torque coefficients were compared with experimental data. The results of error analysis are presented. It was found that the eddy viscosity turbulence models are slightly better in predicting the near field tip vortex flow and the thrust/torque coefficients than the Reynolds stress models. The effect of the grid resolution and distribution and turbulence models on the circumferentially averaged velocities outside the tip vortex region is minimal.