Author(s): Karagiannis N. ; Stampoultzoglou A. ; Prinos P.
Linked Author(s): Panagiotis Prinos
Keywords: Open Foam; Swash flow; Dam break; RNG k-ε; VOF
Abstract: A swash flow numerical model, generated by bore collapse on rough beach slopes, has been developed and implemented using the open source software Open Foam. Numerical results are compared with experimental ones presented by Kikkert et al (2012) .It is the instantaneous generation of such a flow that creates specific turbulent and unsteady conditions in a very short time period which is very difficult for a numerical model to simulate exactly the physical process. RANS (Reynolds averaged Navier Stokes) equations are solved in conjunction with the RNG (Renormalisation Group) k-εturbulence model while VOF (Volume of fluid) method is used for the' tracking" of the free surface. Suitable boundary and initial conditions are chosen with the initial k andεones being extremely important. Numerical velocities and turbulent kinetic energy profiles at specific times, depth average velocities, surface elevation and bed shear stress are presented for different k-εinitial values and are compared satisfactorily with available experimental measurements. Moreover, the k-ωSST turbulence model was also used with different k-ωinitial conditions. Comparison of the computed results indicates that RNG k-εmodel yields better results for this kind of flow. The selection of the turbulence model and the initial conditions is very crucial for the correct simulation of the aforementioned swash flow.
Year: 2015