Numerical Investigation of the Effect of Suspended Load on the Morphology of a Beach under the Action of Tsunamis

Abstract

Fan, F.; Zhu, Z.; Lu, Y.; Yang, B., and Zhao, C., 2020. Numerical investigation of the effect of suspended load on the morphology of a beach under the action of tsunamis. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 174–180. Coconut Creek (Florida), ISSN 0749-0208.To study the morphology of a beach under the action of a tsunami, a beach evolution numerical model based on the open-source calculated fluid dynamics (CFD) code OpenFOAM is constructed. The bed load and suspended load models are fully coupled with the hydrodynamics model in the beach evolution model, and the moving mesh method is used to capture the change in bed morphology. Then, a laboratory experiment on the scour induced by solitary waves is adopted to validate the constructed numerical model, and the surface elevation, bed shear stress and bed profile of the model fit very well with the experimental observations. Finally, the effect of the suspended load on the evolution of beach morphology and the process of beach evolution under the action of a solitary wave are studied with a numerical model. The study results show that the beach evolution mainly occurred at the time the solitary wave ran down and that the suspended load played a major role in the beach evolution, contributing approximately 85% to the scour profile.