Study Of Wave Motion Over Submerged Reefs

In this article, based on wave diffraction theory, boundary element method is applied to study wave motion over submerged reefs. The transmission coefficient, reflection coefficient and the velocity distribution under different conditions such as reefs’submergence, number of arrays, distance between reefs, permeability and the lagoon’s depth are obtained, it is found that:1. Change of the reefs’ submergence has a great impact on reefs’ wave elimination ability, the smaller the depth is, the greater the reefs’ elimination effect will be.2. A single reef is only efficient on the wave elimination of long waves, while an array of reefs have a greater wave elimination effect on medium waves.3. The wave elimination of arrays of reefs will change with arrays distances. When the distance is large, reefs have a better elimination effect on medium waves, but when the distance is small, reefs will be more efficient on long and short waves.4. Porous reefs have less wave elimination effect than impermeable reefs. When the porosity of reefs is increasing, the wave elimination ability will become worse.5. Lagoon reef’s wave elimination ability is determined by lagoon’s depth. The wave elimination effect of lagoon reef on medium and short waves will be better when lagoon’s depth increases. But the elimination effect will seldom increase when lagoon’s depth reaches a certain value.