Author(s): Ali Adel Zuhaira, Harshinie Karunarathna, Dominic E. Reeve
Linked Author(s): Ali Zuhaira
Keywords: Stepped spillways, gabion, energy dissipation, numerical simulation
Abstract: Energy dissipation is one of the most important issues in spillway design as the downstream water flow can be highly energetic, which may lead to the creation of a scour hole in the downstream region. As a means of dissipating energy, stepped spillways can be used. The presence of steps can generate greater flow turbulence dissipating more energy than other types of spillway such as ogee spillways. Gabion stepped spillways are one type of stepped spillway which can offer low construction costs, flexibility, porosity and noise reduction. A 2D numerical model, NEWFLUME, is implemented in this study to simulate flow over different types of gabion spillways. The model is an open source code that solves the Reynolds-Averaged Navier-Stokes equations using a Volume of Fluid technique. A validation of the model is conducted against the experimental data, and good agreement has been found. The model is then set up to investigate a wider range of spillway conditions. Flows over gabion spillways with three different step heights (0. 06m, 0. 09m and 0. 12m) and three different slopes for each step size (1V: 2H, 1V: 2. 5H and 1V: 3H) are investigated. All spillway types are tested with same initial conditions to evaluate the energy dissipation over the gabion steps. The initial results showed that energy dissipation varies with spillway slope and this quantity will play a vital role in the effective design of gabion stepped spillways
Year: 2017