Determination of Resistance forward of an Arbitrary Cross Section of Slow Ships by Means of Velocity Measurements

Abstract

In order to know the contribution of local hull geometry to the resistance of slow full ships, a calculation formula was derived to determine the resistance acting on the hull surface forward of an arbitrary transverse cross section. In determining the resistance use was made of the results of flow measurement at the transverse cross section outside of a ship model.This formula was applied to the two full ship models whose wave resistances were negligibly small. The results of the calculation were found to agree with those based on a higher order boundary layer theory which takes into account pressure variation across the boundary layer. Resistance determined at the control surface right after a ship model was also comparable with towing test result.Applicability of the present method was thus found to be promising, though there exists a room for improvement.