Three-dimensional numerical modeling of water and sediment flow in a sand trap

# Three-dimensional numerical modeling of water and sediment flow in a sand trap

## Abstract

The flow of water in a three-dimensional sand trap is calculated by a numerical model,
using a finite volume method to solve the Navier-Stokes equations for three dimensions on
a general non-orthogonal grid. The k-e turbulence model is used to solve the Reynolds-
stress term. The diffusion/convection equation for the sediment concentration is solved
giving the sediment concentration in the sand trap. A physical model study carried out to
verify the results shows the recirculation zone to be shorter than the numerical model
result, but modifications in the turbulence model give better agreement. The sediment
concentration calculations compare well with the experimental procedures. The
concentration calculated by using the flow field from the original k-e model gives 87.1 %
trap efficiency, whereas calculation with the more correct flow field gives 88.3 %.