Different ways of defining wall shear in smoothed particle hydrodynamics simulations of a dam-break wave

ABSTRACT

The paper describes two different ways of defining the terrain roughness in smoothed particle hydrodynamics (SPH) simulations performed with the Tis Isat model, developed at the University of Ljubljana. The model introduces into the SPH method a non-discrete boundary condition with friction. Two basic definitions of terrain roughness are used: (a) as a hydraulically smooth wall, where roughness was controlled by the wall–particle eddy viscosity coefficient; and (b) as a hydraulically rough terrain by elevating the mesh-nodes. The undertaken SPH simulations relate to a dam break at the upper storage reservoir of the pumped-storage hydro power plant Kolarjev vrh in Slovenia. For the first time, such study was performed on a real topography. Water depths at the gauges along the valley were compared with measurements on a physical model and to results obtained using a finite volume (FV) model. The comparison showed satisfactory agreement with the measurements, which are comparable with the FV model simulations.

Keywords:

• Bed roughness
• boundary condition
• dam break
• HPP Kolarjev vrh
• numerical modelling
• smoothed particle hydrodynamics