INTERACTION BETWEEN WAVES AND HANGING HIGHLY FLEXIBLE KELP BLADES
AbstractThe interaction between waves and flexible blades has drawn recent attention because of the capacity of nature-based infrastructure, such as aquatic vegetation and kelp, to attenuate waves. In this study, a new numerical model was developed to study the wave-blade interaction for both bottom-fixed and suspended blades. The dynamics of the blades simulated by a cable model were coupled with OpenFOAM®-based wave model IHFoam with the immersed boundary method. The results showed that the distribution of the blade-induced vortices was asymmetric with more vortices upstream for the single bottom-fixed blade while more vortices downstream for the single suspended blade. For both submerged and suspended canopies, the vortex distribution is also asymmetric. More vortices concentrate upstream for the submerged canopy. For a suspended canopy, more vortices concentrate upstream and below the bottom of the suspended canopy. Yet near the surface above the suspended canopy, more vortices concentrate downstream. Understanding the distribution of vortices is important for predicting the sediment transport and nutrient distribution.
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