Author(s): A. Nakayama; N. ; Hisasue
Linked Author(s): Akihiko Nakayama
Keywords: Turbulence; Free-surface flow; Filtering; Numerical simulation
Abstract: Formal filtering of turbulent flows of real scale and real geometry with fluctuating free surface has been applied to smooth the flow and the boundaries, both of which have fluctuations of various scales. The filtered equations of motion and the filtered evolution equation of the moving free surface have been obtained. They are not conservative and contain extra terms involving fluctuations with scales smaller than the scale of the applied filter. These terms will need modelling if used as governing equations foe simulation. Actual numerical filtering has been applied to the results of Direct Numerical Simulation (DNS) of open-channel flow to demonstrate the smoothing effects of the filter. The results give better foundation for such numerical simulation methods as Large Eddy Simulation (LES) method that can be applied to realistic free-surface flows such as real river flows.
Year: 2009