On the turbulence-generated free-surface waves in open-channel flows

Abstract

We have performed high-fidelity numerical simulations of a turbulent open-channel flow configuration, accounting for nonlinear wave dynamics at the free-surface. Through analysis of the frequency-wavenumber spectrum, it has been shown that the wave patterns are dominated by turbulent surface fluctuations in almost the entire wave spectrum. On the other hand, propagating surface gravity waves are dominant only at the smallest wavenumbers. The turbulence-induced dispersion was well represented by a diagnostic characteristic frequency which is defined taking into account the nonlinear free-surface kinematic boundary condition. It is shown that for the considered values of parameters, the disper..