NUMERICAL INVESTIGATION ON THE MOTION OF 2-D PARTICLE CLOUDS

Abstract

The motion of 2-D buoyant clouds formed by releasing fine particles into quiescentwaters with finitedepth is numerically studied. In the numerical model, particle phase is modeled by the dispersion model and turbulence is calculated by the large eddy simulation. The governing equations, including the filtered 2-D Navier-Stokes equations and mass transport equation, are solved based on the operator-splitting algorithm and an implicit cubic spline interpolation scheme. The eddy viscosity is evaluated by the modified Smagorinsky model including the buoyancy term. Comparisons of main flow characteristics, including shape, size, average buoyancy, moving speed and the amount of particles depositedon the bed, between experimental and computational results show that the numerical model well predicts the motion of the buoyant clouds in the whole process, from the falling to spreading stage. The effects of silt-fence on the motion of particle clouds are also investigated through numerical experiments.