Presenting a Mathematical Model for Analysis of the Effects of Warp form on the Performance of Planing Hulls

Designing a proper hull-form has always been considered an important issue in hydrodynamics of planing boats. Any small variation of geometry may result in significant changes in boat performance. In the current paper, it is attempted to develop a mathematical model for prediction of the performance of planing boats with variable deadrise in longitudinal direction. To accomplish this task, the 2.5D theory and water impact problem are utilized. Effects of deadrise variation from one section to another has been taken into account in the equations. Hydrodynamic, hydrostatic, and drag forces are determined. A new equation is extracted for computing the whisker spray area. By using the current method, effects of deadrise variation on the hydrodynamic performance of a planing boat are examined. It is concluded that a slight slope variation of deadrise angle may positively affect the performance and lead to a smaller trim angle and resistance in comparison with the prismatic hull-forms.