Analysis of Vegetation Effect on Waves Using a Vertical 2D RANS Model

Wu, W.; Zhang, M.; Ozeren, Y., and Wren, D., 2013. Analysis of vegetation effect on waves using a vertical 2D RANS model. Journal of Coastal Research, 29(2), 383-397. Coconut Creek (Florida), ISSN 0749-0208. A vertical two-dimensional (2D) model has been applied in the simulation of wave propagation through vegetated waterbodies. The model is based on an existing model, SOLA-VOF, that solves the Reynolds-averaged Navier-Stokes (FANS) equations with the finite difference method on a staggered rectangular grid and uses the volume of fluid method to capture the free surface. The model is enhanced in this study by adding the drag and inertia forces in the momentum equations to account for the vegetation effects, implementing the subgrid-scale model for turbulence closure, and incorporating wave-maker, sponge layer, and bottom friction in boundary conditions. The model was first validated using measurement data collected from the literature and then applied to simulate wave propagation in flumes covered by rigid and flexible model and live vegetation. The considered live vegetation species are Spartina alterniflora (smooth cord grass) and Juncus roemerianus (needlegrass rush), which are commonly distributed on coastlines. The model is able to reproduce wave attenuation through the vegetation zone observed in the experiments. The drag coefficients are calibrated in the vertical 2D FANS model and the analytical model based on the wave energy equation and linear wave theory, and the calibrated values in the two models are reasonably close.