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 Boussinesq (GB) numerical model is used to effectively simulate the propagation of cnoidal waves and the associated three-dimensional nonlinear interactions. The numerical computation is based on an Euler predictor-corrector 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 temporal 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 and three-dimensional effects on the forces which cannot be predicted by linear theories. (C) 1996 Elsevier Science Ltd.