Author(s): Wei Wu; Dongfang Liang; Jack Mao Chen
Linked Author(s): Dongfang Liang
Keywords: Solitary waves; Islands; Boussinesq-type equations; Runup; Numerical model
Abstract: This paper employs an extensively validated two-dimensional Boussinesq-type model to examine the interaction between a solitary wave and triple-island clusters. The Boussinesq-type equations are solved using a shock-capturing TVD Lax-Wendroff scheme. This study focuses on the combination effect of two free parameters on the maximum runup, which are the spacing between the adjacent islands and the angle of the three-island group. The maximum runup height on each island is obtained and compared with the isolated-island case. The maximum runups on merged-island, partially-merged-island and separated-island situations are all obtained, and their variations with the aforementioned two parameters are analyzed. It is found that the nonlinear wave diffraction, reflection and refraction play a vital part. Relatively large runups are observed when the triple islands are merged and partially merged, and these large runups generally occur within the narrow gaps between the constituent islands. On the other hand, the island positioned in the shadow of nearby islands is found to experience relatively less impact. These results offer some guidance for designing the height of coastal defenses.