Approximate Calculation of Ship Frictional Resistance Increase due to Surface Roughness

抄録

In order to calculate frictional resistance increase due to surface roughness of a ship, a two-dimensional turbulent boundary layer theory for rough surface was applied to potential streamlines over the hull surface. In the calculation, Karlsson's roughness functions for full-scale ships were used. The calculated results were compared with those calculated by replacing a ship with a flat plate, and compared with the experimental data. The frictional resistance increase calculated by the present method is a little larger than that of flat plate approximation. Further, a fairly good correlation between calculated results and experimental data was obtained when they were plotted with respect to the mean apparent amplitude.