Particle-laden currents interacting with complex bottom topography: a numerical investigation

Abstract

We conduct depth-resolved three-dimensional Direct Numerical Simulations (DNS) of bi-disperse turbidity currents interacting with complex bottom topography in the form of a Gaussian bump. Several flow characteristics such as suspended particle mass, instantaneous wall shear stress, transient deposit height are shown via videos. Furthermore, we investigate the influence of the obstacle on the vortical structure and sedimentation of particles by comparing the results against the same setup and but with a flat bottom surface. We observe that the obstacle influences the deposition of coarse particles mainly in the vicinity of the obstacle due to lateral deflection, whereas for the sedimentation of fine particles the effects of topographical features are felt further downstream. The results shown in this fluid dynamics video help us develop a fundamental understanding of the dynamics of turbidity currents interacting with complex seafloor topography.