Directional Effects on Sinkage, Trim and Resistance

Abstract

The influence of fore-and-aft asymmetry of a ship is known to be ignored in the classic thin-ship theory for resistance. In the current work, a more sophisticated approach is utilized in which the sinkage and trim are accounted for within the framework of the same theory. It is shown that the enhanced computer program correctly predicts that vessels with the centre of buoyancy forward of midships suffer a greater sinkage. In addition, the trim is relatively more by the bow. Finally, it is demonstrated that the inclusion of the effects of sinkage and trim in the analysis results in a slightly increased resistance for vessels with the centre of buoyancy forward of midships, in keeping with the experimental evidence.