Trajectory-Diffusive Mechanism of Desilt Basin Operation

Abstract

Within the framework of the generalized theory of turbulent diffusion, we consider the mean velocities, times, length of alternating transverse up-and-down motion of suspended particles in sediment exhibiting different settling velocities and fluid particles in calm uniform wide open flows. Experimental data obtained by various authors are used to find the maximum heights and lengths of particle saltation in the thin near-bottom region, as well as the magnitude of the dynamic flow velocity, which triggers the motion of particles on the bottom. From the combined trajectory description of particle motion in sediments of different settling velocities over the entire depth of an open flow, the trajectory limit settling velocity of suspended sediments deposited in a rectilinear desilt basin may be determined and, within the framework of relaxation models, the length of silting and erosion at the bottom may be found.