Numerical analysis of the hydrodynamic interaction between a propeller and trapezoidal rudder

Abstract

The wake evolution of the propeller–rudder system is crucial to the noise performance of the vessel. The rudder operating in propeller wake impacts the distribution of turbulence in the propeller wake. Hence, the hydrodynamic interaction between the propeller and trapezoidal rudder is investigated. The asymmetric distribution of the pressure on the rudder is analyzed. The evolution of rudder tip vortex and propeller vortices in the downstream is discussed. The impact of trapezoidal rudder on the asymmetric evolution of propeller wake and turbulence is studied. The results suggest that the trapezoidal rudder induces asymmetric distributions of the pressure on the rudder. Pressure fluctuations in the rudder tip vortex can be strengthened by the interaction between the rudder tip vortex and propeller tip vortices. The turbulence in the downstream is enhanced by the interactions among propeller hub vortex, propeller tip vortices, rudder trail vortices and rudder tip vortex. Different to skew-symmetric distribution of turbulence induced by rectangular rudder, trapezoidal rudder leads to completely asymmetric evolution of propeller wake and then completely asymmetric distributions of turbulence. The impact of the rudder geometry on the wake evolution indicates that the turbulence in the propeller wake can be adjusted by optimizing rudder geometry.