Abstract
In open-channel turbulent flow, changes in flow features often appear on a water surface. Therefore, water surface is subjected to various influences but its characteristics about the source of surface variation, fluctuations and advection of surface features are not fully understood. In the present research, in order to investigate advection characteristics and source of water surface fluctuations, experiments by PIV and numerical simulations by LES are conducted for an open-channel flow with strip roughness. As a result, cross-correlation analysis of water surface fluctuation made it clear that advection characteristics of water surface fluctuation with strip roughness wall are different from the on smooth wall. Moreover, it was found that water surface fluctuation due to bursting phenomena from near bottom wall is dominant by using a Pre-Multiplied Spectra.
