Author(s): C. W. Li; J. J. Li
Linked Author(s): Chi Wai Li
Keywords: DANS model; Numerical model; Open channel flow; Gabion channel; Gravels
Abstract: A Double Averaged Navier Stokes equation (DANS) model is proposed to simulate flows in gabion channels. Turbulence is modelled by the Spalart-Allmaras closure with a modified length scale which is dependent on a zero-planedisplacement parameter relating to the gravel characteristics. The dispersive stress is modelled by a sub-length scale closure, similar to the Smagorinsky model used in Large Eddy Simulation (LES) .The model has been applied to a case of flow over two dimensional bar roughness and a case of flow over gravels. The velocity and Reynolds stress profiles are predicted correctly. The dispersive stress peaks at the correct level and with right magnitude through calibration. The DANS model is useful for the study of the turbulent mixing phenomenon in the gravel layer where the dispersive stress is of the same order of the Reynolds stress.
Year: 2015