Three- Dimensional Modeling of Wave- induced Flow Inside and Aroend Vertical Permeable Breakwater

Stones insiderubble mound breakwaters are coated with biofilm. Microorganisms live one the surfaceof biofilm are understood to have natural water purification function by bio ogical processes. Therefore, a perforated caisson type breakwater filled with rubble gives contribution to water purification besides wave attenuating function. The flow and travel time of water particle through this structure have important influence on the microorganism function and therefore should be studied in detail. Several analyrical and numerical solution models have been proposed on this subject by now with some assumptions. which make their application limited. Here, a new fully three-dimensional couple Eulerian-Lagrangian nonlinear model is developed based on VOF model (Hirt and Nichols. 1981) and modified resistance forces (Mizutani, 1996) to deal with the porous media and water waves interaction as well as consideration of the size effect of porous medium (Fig.l).