A Semiempirical Computerized Method for Predicting Three-Dimensional Hull-Water Impact Pressure Distributions and Forces on High-Performance Hulls

The report describes the development and usage of a semiempirical, quasi-static computerized method for calculating instantaneous three-dimensional water pressure distributions on high-speed marine vehicles. The method can simulate either planing or hull-wave impacts in three degrees of motion--pitch, heave, and surge. The analysis technique requires hull offsets, trochoidal wave parameters, and such initial condition information as the hull position, the vertical and horizontal velocity components, and the pitch rate. The method can be used to obtain results of varying complexity, including a description of normal pressures for all or selected portions of the hull, a normalized pressure versus impact area relationship, and horizontal and vertical impact forces.