Effect of particle inertia on the dynamics of depositional particulate density currents

Abstract

In this work we address the effect of particle inertia on depositional particulate density currents. We employ a two-fluid model based on the equilibrium Eulerian approach and present highly resolved two-dimensional (2D) simulations of the flow for a Reynolds number of 3450 (this particular choice corresponds to values of Grashof number Gr of 1.5 × 10 6 ).The simulations capture physical aspects of two-phase flows, such as particle preferential concentration and particle migration down turbulence gradients (turbophoresis), which modify substantially the structure and dynamics of the flow. In the simulations we observe the migration of particles from the core of Kelvin–Helmholtz vortices shed from the front of the current as well as their accumulation in the current head. This redistribution of particles in the current affects the propagation velocity of the front, bottom shear stress patterns, as well as deposition rates and patterns.