Iterative dual boundary element analysis of a wavy porous plate near an inclined seawall

Abstract

In this work, wave trapping characteristics of a permeable composite wavy barrier located near an inclined seawall are examined under the framework of linear potential flow theory. For the waves past the thin barrier, a semi-empirical discharge equation having a quadratic pressure drop along with the velocity continuum is considered. The boundary value problem is solved using the dual boundary element method (DBEM). The accuracy of the numerical results is ascertained with a numerical model based on an independently developed multi-domain boundary element method (MBEM). Various numerical results such as wave reflection, wave run-up, the vertical force on the barrier and horizontal force on the wall are discussed considering various values of barrier porosity, number of ripples, ripple amplitude, relative spacing between the wall and barrier, relative submergence depth, seawall inclination, and seawall porosity. The numerical results suggest that the performance of the wavy barrier within sight of partial reflection leeward inclined wall is marginal for the design of the development of breakwaters as contrasted to the vertical and seaward inclined wall. The ripple amplitude minimizes the vertical force on the wavy barrier and the reduction is 63% for the non-dimensional ripple amplitude a/B=0.25 as compared to a flat plate where ‘a’ and ‘B’ refers to ripple amplitude and plate width respectively. The parametric study is expected to serve as an incentive for the design and development of composite wavy porous plates to secure the available seawalls.