The purpose of this paper is to present the free-surface flows in generalized coordinate system. The model is based on the two dimensional unsteady Reynolds equations for the mean flow. Turbulence closure model is obtained by a two-eqation model consisting of transport equations for the turbulence kinetic energy (k) and its dissipation rate (ε). To handle arbitrary geometries, the boundary-fitted curvilinear coordinates are used to generate a coodinate surface coincident with the rigid boundary and free-surface boundary in the physical plain. Consequently, we can use accurate boundary conditions at a free-surface. The solution procedure for the convective terms in the momentum equation and turbulence transport equations uses spatially third-order accurate upwind QUICK control-volume algorithm that is extended to generalized coordinates. The computations for the turbulent flow in a steep-sided trapezoidal trench placed perpendicular to the mean flow direction and in a complicated enclosure passage with upper free-surface bounary are made with a computer code named kεGGQ2D/surf. The results are in fine agreement with the experiments in velocity and pressure profiles.

View full abstract