Large Eddy Simulation Of Turbulent Flow In Open Channel With Vegetated Domain

This work is under the project 'numerical study of turbulent flow in open channel with a vegetated region'. Two numerical models have been proposed and developed by using the technique of large eddy simulation (LES). Model verification and applications have been carried out subsequently.For the present two LES models, adopting the subgrid eddy viscosity concept and introducing the transport equation of turbulence energy k, the subgrid scale turbulence is parameterized by the turbulence energy k and the length scale of turbulence / (k-1 model). In addition, vegetation is considered as an internal source of resistant force and turbulence energy.For problems with emergent vegetation, a. quasi-3D LES model named k-1 LES has been set up for shallow water situation. Applying the proposed model, the turbulent flow in open channel with emergent vegetation region has been simulated and the flow effect due to vegetation has been analyzed.Furthermore, for problems with submerged vegetation, a 3D LES model named 3D k-1 LES has been set up. Applying the proposed model, the turbulent flow in open channel with submerged vegetation has been simulated and the flow effect due to vegetation has been analyzed.The computational results of models are in satisfactorily agreement with the experimental data. All the results show the validity of the proposed models. The present k-l LES and 3D k-l LES model are proven to be new useful tools for the study on turbulent flow in open channel with a vegetated region.