Installing single-propeller twin-rudder system with less asymmetric maneuvering motions

Abstract

The inflow characteristics to each one of the rudders of single-propeller twin-rudder system are investigated. It is shown that this inflow is not parallel to ships centerline. This may result in asymmetric maneuvering characteristic of the ship thereby reducing ships maneuvering performance. For this purpose, a method of installing single-propeller twin-rudder system is proposed. This method is called virtual zero rudder angle arrangement. Here, each one of the twin-rudder is set at an angle corresponding to the inflow to the rudder. The improvement in ships maneuvering characteristics with virtual zero rudder angle arrangement is investigated using experiments and numerical simulations for different ship types. It is shown that this arrangement may also improve ships propulsion performance. ? 2011 Elsevier Ltd. All rights reserved.