Investigation of the propeller slip stream over an Azipod propulsor by PIV measurements and CFD simulations

In the following study the possibility to simulate the propeller slip flow over a pod propulsor has been investigated. The slipstream can be investigated either through measurements or by calculations. Since the measurements had to be done in model scale all the comparisons have been done in that scale. For this study a pod unit with a working propeller was experimentally investigated using the particle image velocimetry (PIV) method. This was done at two differentadvance ratios. The same condition was then investigated both with a boundary element method (BEM) and Unsteady Reynolds Averaged Navier-Stokes (URANS) calculations. In the URANS approach both SST (Menter) k-ω and Reynolds stress transport (RST) turbulence models were used. The RST model takes into account the anisotropy of turbulence. From the calculation methods there are clear differences in the approach. The BEM has its unknowns on the surface onlyand computes field quantities as a post-processing step. The URANS on the other hand incorporates calculation cells between the calculation surfaces and the plane of intererest, and hence, takes into account the volume of the fluid.