AbstractRecently, Larsen and Fuhrman (2018) have shown that seemingly all commonly used (both k-omega and k-epsilon variants) two-equation RANS turbulence closure models are unconditionally unstable in the potential flow beneath surface waves, helping to explain the wide-spread over-production of turbulent kinetic energy in CFD simulations, relative to measurements. They devised and tested a new formally stabilized formulation of the widely used k-omega turbulence model, making use of a modified eddy viscosity. In the present work, three new formally-stable k-omega turbulence model formulations are derived and tested in CFD simulations involving the flow and dynamics beneath large-scale plunging breaking waves.
Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/T2fFRgq3I8E
Larsen, B.E. and Fuhrman, D.R. (2018). On the over-production of turbulence beneath surface waves in Reynolds-averaged Navier–Stokes models. J. Fluid Mech., vol. 853, pp. 419–60.
van der A, D.A., van der Zanden, J., O'Donoghue, T., Hurther, D., Caceres, I., McLelland, S.J. and Ribberink, J.S. (2017). Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar. J. Geophys. Res.: Oceans, vol. 122, pp. 3287-3310.