Author(s): Dimitrios K. Fytanidis; Jose M. Mier; Blake J. Landry; Marcelo H. Garcia
Linked Author(s): Marcelo García
Keywords: Oscillatory flow; Near equilibrium conditions; Bed shear stress modeling
Abstract: Coastal processes and seabed mechanics are influenced by Oscillatory Boundary Layer (OBL) flows. The presence of a phase lag between the bed-shear stress and free-stream velocity maxima in oscillatory flows has puzzled the coastal sediment transport and fluid mechanics community. Fytanidis et al. (2021) and Mier et al. (2021) used Direct Numerical Simulations and Laser Doppler Velocimetry (LDV) measurements to explain inconsistencies in the literature, such as the second burst of sediment entrainment commonly observed in oscillatory sheet flows and sediment transport in time-varying flows. Methods Detailed Laser Dopler Velocimetry experimental observations performed in the Large Oscillatory Water and Sediment Tunnel (LOWST) housed at the Ven Te Chow Hydrosystems laboratory (University of Illinois) (Fig. 1a) were combined with Direct Numerical Simulations (Fig. 1b) were used to analysis the time variation of velocity and bed-shear stress under a wide range of Reynolds numbers.
Year: 2024