Two-dimensional Numerical Analysis on the Flow and Turbulence Structures in Artificial Dunes

Turbulence is one of the decisive parameters that cause scouring in the river bed and threaten the foundation of hydraulic structures. And choosing the right turbulent modeling scheme is the key to simulate this flow property accurately. This study investigated a turbulent flow in a scour hole developed in a channel by using OpenFOAM toolbox. Two different turbulence schemes, k-epsilon and k-omega, were used to evaluate the performance of turbulent schemes in simulating the turbulence property in this complex region. Beside the main turbulence schemes, the difficulties in modeling the flow close to the wall also was solved by choosing the right wall function and boundary conditions. The results from these two models, the flow velocity profiles in streamwise and water-depth directions as well as the turbulent kinetic energy, were evaluated by comparing with the physical experimental data from previous research.