Wave propagation on steep slope of submerged reefs

Abstract

The main topography of the islands in the Truong Sa archipelago is coral reefs with the feature that reef face is a steep slope, then the reef. The water depth on the reef of some islands varies with the tide from 2m to 6m (depending on the island region). In the world and in Vietnam, there have been many studies on wave transmission across submerged reefs, but there are still many issues that have not been fully studied. This paper presents a study on the simulation of wave transmission across submerged reefs which have a steeply slope of 1/5 and a small water depth on the reef (suitable for reality in the Truong Sa Islands) using numerical modelling (Ansys Fluent) and compared with the results of the physical experimental model. The main research results show that the incident wave height is greater than the water depth on the reef, the wave will break at the top of the slope and the height will decrease but it can be greater than the water depth when propagating into the island. In case the incident wave height is less than or equal to the water depth on the reef, the wave will not break on the reef, the wave height is limited by the ratio 0.78d (d is the water depth).