Numerical Investigation of Solitary Wave Interaction with a Submerged Vertical Thin Barrier

• Main Authors: Yun-TaWu, 吳昀達
• Other Authors: Shih-Chun Hsiao
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/34018275440878931247

碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 98 === This study presents the numerical results of wave-structure interaction of a solitary wave propagating over a vertical thin and rigid barrier using the two-dimensional volume of fluid (VOF)-type numerical model named COBRAS (COrnell BReaking And Structure). The present numerical model solves the Reynolds Averaged Navier-Stokes (RANS) equations for describing mean flow motion of essentially any Newtonian fluid. The modified k-ε turbulent closure solver for simulating turbulence behaviors is also incorporated. The volume of fluid (VOF) method is used to trace the free surface motion. In this study, the solitary wave is generated through the boundary by specifying both free surface elevation and velocity components. To minimize the computational domain, active wave absorption inflow boundary condition is also included, which allows the inflow boundary for generating desired waves and at the same time absorbing reflected waves (Torres-Freyermuth et al., 2010). The model simulation capability is first validated against the laboratory experiments of Yasuda et al. (1997), which focused on breaking solitary waves passing through an impermeable shelf. Comparisons between the experimental data and present numerical results are in good agreements. Then, a set of numerical tests is carried out for a solitary wave propagating over a vertical thin barrier with various wave non-linearity (defined as the ratio of incident wave height to water depth) and two types of thin barrier’s setup. In particular, the characteristics of variation of wave reflection, transmission and dissipation due to flow separation and wave breaking, the vortex generation and evolution in the vicinity of thin barrier, and the turbulent kinetic energy (TKE) behavior are summarized and discussed.