Velocity scaling in open-channel flows with sediment transport

Abstract

Under uniform and non-uniform flow conditions, the most employed velocity scale in OCFs is the shear velocity. In non-uniform flow conditions with sediment transport, the log-law velocity distribution could be absent, so it is not possible to apply the conventional methods to compute the shear velocity. This work aims to define a way to compute the best value of velocity scale in non-uniform flows with different sediment transport under the absence of the log-law velocity distribution. Laboratory tests were performed by using a PIV system to measure the time and space velocity vectors, the total shear stress profiles were computed through the momentum balance analysis and the co-spectrum of the velocity fluctuation to define different values of the velocity scale factor. To determine which of the different values gives the better scaling of the velocity profiles, a comparison of the non-dimensional velocity profiles was done by showing that the value at the crest level from a linear regression of the shear stress profile, obtained with the momentum balance analysis, is the best velocity scale value.

Numerical Simulation of Slope–Gully–Stream Sediment Transport Process with Water and Gravity Erosion

“…Water erosion and gravity erosion are two main forms of soil erosion, exhibiting different subsequent sediment transport processes. The particle and fluid velocities and sediment transport were studied using many new physical equipment, such as an Acoustic Doppler Current Profiler and Particle Image Velocimetry (Kostaschuk et al, 2005;Corapi et al, 2021). Our results show the same laws and trends with these study in general, however, the specific quantities and processes are different.…”