Smooth and Stepped Spillway Modeling Using the SPH Method

The smoothed particle hydrodynamics (SPH) method was used to simulate the flow over smooth and stepped spillways in the nonaerated, skimming flow regime. Two-dimensional numerical simulations were carried out using the DualSPHysics software and compared with experimental data on a 2H:1V sloping spillway for smooth and stepped inverts. Continuous inflow fluid layers with constant height and uniform velocity were used to establish the flow rate on the broad crested weir. The ability of the SPH to reproduce the main flow characteristics was analyzed by comparing the numerical flow depths and velocity profiles with their experimental counterparts. Firstly, a convergence analysis was carried out for various initial particle spacing. The flow characteristics along the stepped spillway were more sensitive to the particle spacing compared to the smooth chute one. In general, the numerical flow depths compared well with the corresponding experimental data and with empirical formulas available in the literature. The velocity profiles, and the free-stream velocity in particular, were also well reproduced by the SPH method; however, larger differences were obtained near the solid boundary.