Numerical modeling of nonlinear surface waves caused by surface effect ships dynamics and kinematics

Abstract

We model fully nonlinear free surface waves caused by a translating disturbance made of a pressure patch and/or a surface-piercing body (ship), within the framework of potential flow theory. The three-dimensional higher-order Boundary Element Model by Grilli et al. (2001) and Fochesato et al. (2004) is utilized with some recent extensions. In addition to the regular Eulerian-Lagrangian updating of the free surface geometry and potential, based on higher-order explicit Taylor series expansions, a pseudo-Lagrangian updating algorithm is developed to express and solve the problem in a coordinate system traveling at the instantaneous speed of the moving disturbance. This paper presents theoretical developments and applications illustrating both the accuracy and efficiency of the present method for a traveling pressure patch and an advancing Wigley hull. Based on numerical results, it is concluded that the present numerical approach, with a pseudo-Lagrangian updating and a higher-order BEM provides accurate and efficient results. Copyright ？ 2005 by The International Society of Offshore and Polar Engineers.