Evaluation of the Propeller Hull Vortex using a RANS solver

The appearance of the propeller hull vortex (PHV) has been investigated using the FINFLO RANS solver. This specific phenomenon occurs when solid surfaces placed in the neighbourhood of the propeller prevent the natural flow contraction resulting from the local flow acceleration. As the propeller blades near the solid surfaces may not obtain enough mass flow from the inlet - i.e., the propeller is starved of water - the flow may reverse locally so that water is sucked from the outlet. The small tip clearance combined with the low advance number as well as the geometry of the solid surfaces may affect the inception of the PHV. Time-dependent computations were carried out at seven advance numbers. During the analysis of the results, several quantities were examined to detect the inception of the PHV. Streamlines were found to be the best technique to trace the vortices from an extremely complex flow field. The flow patterns on the flat plate were compared to published experimental observations using the limiting streamlines along the plate. Flow patterns similar to those discovered in the experiments were also obtained by RANS simulations, so the RANS method is able to predict the occurrence of the PHV at least on a qualitative level