RANS and PANEL Method for Unsteady Flow Propeller Analysis

A spatial non uniform inflow is the usual inflow to which a marine propeller is subjected to. Inside a ship wake, in inclined shaft condition, in tandem/contra rotating configurations, the spatial non uniformity of the incoming flow on the propeller plane leads to the unsteadiness responsible of thrust and torque fluctuations, induced pressures, cavitation and the associated noise. Any design method and, moreover, each analysis tool should be able to treat these phenomena, to carry out a more consistent ship oriented propeller design and to better understand the flow features and the performances of an already designed propeller. In the present work two different numerical approaches, a commercial RANS solver and a in house developed Panel Method, are addressed and applied for the analysis of marine propellers subjected to an oblique inflow, showing, through the comparison with the experimental measures, their capabilities and their limitations.