HYDRODYNAMIC INTERACTIONS OF CNOIDAL WAVES WITH A VERTICAL CYLINDER

This paper describes a study of the diffraction of periodic nonlinear shallow water waves around a vertical cylinder. The generalized Boussi nesq (GB) numerical model is used to effectively simulate the propagat ion of cnoidal waves and the associated three-dimensional nonlinear in teractions. The numerical computation is based on an Euler predictor-c orrector algorithm in a curvilinear coordinate system. An approximate second-order cnoidal wave solution for the GB equations is derived and used to provide the initial and incident wave conditions. The tempora l and spatial evolution of an incident cnoidal wave after interacting with a cylinder is presented. The maximum force acting on the cylinder is also computed. The GB model simulation predicts strong nonlinear a nd three-dimensional effects on the forces which cannot be predicted b y linear theories. (C) 1996 Elsevier Science Ltd.