Experimental Study and Numerical Simulation on Hydrodynamic Performance of a Twisted Rudder

Abstract

AbstractTo analyze the energy-saving effect of a twisted rudder, this work presents the simulated and experimental results of propeller-rudder systems. In this article, a surface panel method (SPM) and computational fluid dynamics (CFD) are introduced to simulate the hydrodynamic performance of propeller-rudder systems. The thrust coefficient Kt, torque coefficient Kq, open-water efficiency η of the propeller, and thrust coefficient Kr of the rudder as a function of the advance coefficient J are obtained and plotted. The energy-saving effect of the twisted rudder is analyzed by comparing the results of numerical simulation and a cavitation tunnel experiment. The experimental energy-saving effect is 2.23% at the design advance coefficient J = 0.8. The pressure distributions of the propeller blade and rudder are plotted by two methods, and the difference of the force on an ordinary rudder and a twisted rudder is discussed. This study improved the experimental twisted rudder model. The change makes the rudder take advantage of propeller wake and improves the energy-saving effect of a twisted rudder. After improvement, the energy-saving effects obtained by the two methods are 0.448% and 0.441%. To analyze the energy-saving mechanism, this study compares the pressure distributions and efficiencies of different systems.