Abstract:
This paper is aimed at presenting i) a simple, yet sound, conceptual model applicable
to the simulation of erosion, deposition and transport of cohesionless
sediment in stratified flows under high shear stresses and ii) numerical solutions
in idealized unsteady flow non-equilibrium transport situations. The conceptual
model for the granular phase comprises 2DV mass and momentum and energy
equations and constitutive equations, all derived within the dense limit of the
Chapman-Enskog kinetic theory. 1D shallow-flow conservation and closure equations
are derived for the fluid-granular mixture. Formulas for the average velocity
in the transport layers, the vertical net flux of sediment mass and the thickness of
the transport layer are thus obtained. Numerical solutions for dam-break flows
over cohesionless mobile beds in prismatic and non-prismatic channels are obtained
and discussed.
