HYDRODYNAMIC BEHAVIOR OF PARTLY VEGETATED OPEN CHANNELS

The hydrodynamic response of turbulent flow in a compound wide rectang ular open channel with a vegetated domain at the channel bank, in a ch annel corner and in a floodplain, to the vegetation density and diamet er is discussed. To this end a phenomenological model was imbedded in an algebraic stress model with the vegetation modeled as an internal r esistance that exerts drag force, produces energy of turbulence, and i nterferes with its anisotropy and length scale. Simple suggestions for some modeling problems associated with the presence of wide vegetated domains are used to yield the three-dimensional flow. Vorticity sourc es relaxation was implemented to smooth periodic behavior, and dissipa tion correction was introduced as a coordinate-invariant damping. With these, the results represent fully developed flow.