Analysis of the performances of a marine propeller operating 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 analyzed at different incidence angles (10–30°) in order to characterize 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 and downstream wake will be presented as well. Verification of the numerical computations have been assessed by grid convergence analysis.

► Marine propeller functioning in idealized off-design conditions. ► Accurate quantification of loads and moment in the propeller plane. ► Details of pressure field and propeller wake characteristics at incidence. ► Assessment and improvement of low order models for complex CFD simulations.