CFD Analysis of Propeller Performance in Oblique Flow

The present work is aimed to assess the capability of a numerical code based on the solution of the Reynolds averaged Navier--Stokes Equations for the study of propeller functioning in off design conditions; this aspect is becoming of central interest in naval hydrodynamics research because of its crucial implications on design aspects and performance analysis of the vessel during its operational life. A marine propeller working in oblique flow conditions is numerically simulated by the unsteady Reynolds averaged Navier-Stokes equations (uRaNSe) and a dynamically overlapping grid approach. The test case considered is the CNR-INSEAN E779A propeller model. Two different loading conditions have been considered at different incidence angles (10° to 30°) in order to analyze the propeller performance during idealized off-design conditions, similar to those experienced during a tight manoeuvre. The main focus is on hydrodynamic loads (forces and moments) that act on a single blade, on the hub and on the complete propeller; peculiar characteristics of pressure distribution on the blade will be presented as well. Verification of the numerical computations have been asses sed by grid convergence analysis.