Analytical Modeling of Mean Velocity Profile through Two-Layered Fully Submerged Vegetation

Abstract

The mean velocity distribution of open channel flows with fully submerged two-layered vegetation can be divided into three zones. Zone 1 represents the lower region of short vegetation, where the flow has high drag because of highly dense vegetation, Zone 2 represents the middle flow zone from the edge of the short vegetation to the top of the tall one, and Zone 3 denotes the upper region with the free surface flow. A new analytical model is developed based on the momentum equation of vegetated flow, where turbulent eddy viscosity is approximated as a linear relationship with local velocity. The analytical model was evaluated using seven experimental data sets under different flow conditions with distinctive densities and formations of vegetation. Three sets of data available from other researchers were also used to check the applicability of the proposed model. An agreement between the analytical model and experimental data indicates the validity and robustness of the model.