Author(s): D. Zagar; E. Dzebo; M. Cetina; G. Petkovsek
Linked Author(s):
Keywords: Dam break; SPH; Numerical modelling
Abstract: The accumulations of pumped-storage hydro power plants are usually encircled by artificial embankments at locations where partial dam breaks can have devastating consequences. Numerical modelling of the free surface flow of such dam breaks is a challenge because high velocities on very steep terrain and the curved narrow valleys give rise to phenomena that are difficult to describe using finite differences, finite volumes of finite elements methods. The smoothed particle hydrodynamics (SPH) method provides the best description of the surge front and free surface in such conditions. A case study was performed on a pumped-storage hydro power plant Kolarjev Vrh (Slovenia), where an accumulation is planned with a volume of approximately3.1 million m3and 715 m difference in altitude. A potential dam break would result in a flow of approximately 20 000 m3/s down a narrow valley, where slopes locally reach 20% (14% on average), reaching the plain in a few minutes. The topography of the terrain and accumulation was established on the basis of topographic maps and measurements and the outflow discharge hydrograph is a result of previous studies. The SPH method was used to simulate the outflow from the accumulation and flow through the valley until water reaches the plain. The SPH simulation results were compared to measurements of a physical model and results provided by a different mathematical model (two-dimensional, curvilinear orthogonal grid, control volumes method). Good agreement of the surge front approach time was found between both models and measurements. However, the SPH simulations resulted in relatively large oscillations in water levels. This is probably due to large particle size. Simulations with a larger number of smaller particles are underway, while in the future, the use of multi-processor platforms is also considered.
Year: 2009