A Study on the Estimation of Rudder Resistance behind Ship

Abstract

Comparing with experimental results, the rudder resistance calculated by NICE-code is overestimated in self propulsion condition particularly. This causes bad influence upon the accuracy of calculated self propulsion factors, for example 1-t etc. In this study, the arrangement of grid near the leading edge is studied to calculate the rudder resistance accurately. First, the viscous flow field around a two-dimensional Joukowski aerofoil is computed with H-type grid. As suggested by the potential theory, fine grids are needed near the leading edge to follow numerically the very steep pressure gradient there. Secondly, the fine grids are applied to compute the viscous flow field around the rudder behind ship. As the result, estimated rudder resistance with finer grid, shows better agreement with experimental results.