Numerical modeling of free and submerged labyrinth weir flow for a large sidewall angle

In recent decades, the advancement of knowledge on the hydraulics of labyrinth weirs has resulted mainly from physical modeling. In this study, numerical simulations of free-flow and submerged labyrinth weirs were conducted for a large sidewall angle, using commercially available computational fluid dynamics software, for three different turbulence models. These simulations were compared with experimental data gathered in a fairly large-scale facility. In general, very good agreement was found on the discharge capacity, in free-flow and submerged conditions, regardless of the turbulence model tested. A dimensionless approaching free surface profile, which was virtually independent of the relative upstream head, was obtained. Downstream of the weir, under subcritical flow conditions, the numerical flow depths agreed reasonably well with the corresponding experimental data.