Second order wave diffraction forces and runup by finite—infinite element method

Abstract

This paper presents a finite-infinite element method for solving the second order wave diffraction problem. The formulation of the problem is based on the inhomogeneous far field condition and its corresponding higher order asymptotic solutions for the second order diffracted potential suggested by Li 9 , and follows the finite-infinite element method as used by Lau and Ji 18 . The interpolation in the infinite element along the radial direction has a far field decay rate compatible diffraction by a vertical surface-piercing circular cylinder. Numerical solutions of the second order diffracted potential, satisfying all the governing and boundary conditions as well as the inhomogeneous far field condition, are obtainable with the method. Numerical tests of the method give very good results of wave forces and runup profiles when compared with those published by other researchers.