On Scale Effect for Hydrodynamic Characteristics of Rudders behind Ships.

Abstract

A calculation of normal forces acting on the rudders behind some typical ships is performed to clarify the possibility of the stabilization of the manoeuvrability in a ship compared with the model. The effects of the propeller slip-stream and the drift angle of the ship are taken into account. The calculation method is based upon the linear vortex line theory both for the rudder and the propeller. When the wake of a ship is large and the ratio of the rudder height to the diameter of the propeller is large, a possibility of the larger turning moment by the rudder in a ship compared with the model is shown.