A METHOD FOR COMPUTING STERN FLOWS WITH AN OPERATING PROPELLER

The flow prediction method presented in this paper is based on the Reynolds-Averaged Navier-Stokes equations, which are discretised using a finite analytic scheme in a body-fitted co-ordinate system. A standard two equation turbulence model is employed. To represent the propeller, body forces are introduced in the axial and tangential directions at the location of the propeller disk. The forces applied are obtained from a lifting line propeller analysis method, which is run interactively with the Navier-Stokes method. Since the theory of the Navier Stokes method and the grid generation has been presented elsewhere, at short introduction only is given in the paper. More emphasis is placed on the present extension of the method to include the propeller effect. Three test cases are presented. First the predictions for an open water case are compared with measurements by Voigt. Thereafter, results are given for an axisymmetric body with and without an operating propeller. Comparisons are made with measurement data by Huang. The agreement with the data is very good in both cases. Finally, the three-dimensional flow around the stern of a ship hull is predicted with and without the propeller. Good agreement with the data of Toda et al is noted.