Three-dimensional numerical modelling of curved open channel using non-hydrostatic turbulent finite element solver for free-surface flows

A novel three-dimensional model for a free-surface without the conventional hydrostatic pressure assumption has been applied to simulate the curved channel flows. Using the unstructured grid the finite element solver adopts the so-called Raviart-Thomas finite element in the horizontal plane and the conventional linear galerkin finite element in the vertical direction. The fixed strata system is used in the vertical plane and this procedure allows accurate grid resolution at the bed and the free-surface. A time-marching scheme is achieved by using the fractional three-step semi-implicit method while the characteristic method is used for the computation of convective terms. A new algorithm is used for the κ - ε turbulence solver, and the related algebraic eddy coefficients are modified to account for some anisotropic and the related secondary effects appearing in the curved open channels flows. The model is applied successfully to the three-dimensional unsteady curved open channel flow for which experimental data are available for comparison. © 2005 Elsevier Ltd