Flow Hydrodynamics in A Multistage Compound Channel with Riparian Vegetation

Abstract

In the area that, occasionally inundated by flood, it is essential to understand the behavior of adjoining floodplains while avoiding flooding. The forecast of lateral velocity distribution across entire river cross-section is essential to solve hydro-engineering and river-related complications. FLUENT, a 3-D numerical code, was used with Reynold stress model (RSM). This paper proposes efficient two stage floodplain for exploring the distribution of lateral velocity in a non-symmetric compound channel. Using the RSM, it is pertinently observed that the forecast of the lateral depth average velocity distribution of numerical model coincides with the observed experimental calculations used for validation. The effects of the emergent vegetation of the floodplain were identified by using an asymmetric compound channel:150 cm length,100cm wide flume. Vegetation model used consisted of 0.5cm diameter and 15cm height cylinder, placed along the junction edges. A deceleration in the flow velocity gradient in the first and second terrace of vegetated floodplain show a dominant role in momentum exchange and increase Reynold stresses near vegetation area.