Numerical Simulation of Turbulent Rayleigh-Taylor Instability Induced by Suspended Fine Sediments

This study presents a two-way coupled Euler-Euler model to simulate the dilute suspension of fine particles in liquid flows. A series of numerical experiments on the particle-induced Rayleigh-Taylor instability is carried out to investigate bulk mixing attributable to the initial concentration. This study identifies deviations in the current two-phase simulations by comparing them with singe-phase approximations. The results indicate that the deviations are caused by non-equilibrium particle inertial and mixture incompressibility. In the dilute suspension, it is found that the non-equilibrium particle inertial enhances vertical motion of bubbles and spikes, resulting in a higher efficiency in vertical mixing. However, as initial concentration increases, the influence of mixture incompressibility becomes more pronounced and is able to induce a significant suppression of upward-moving motions of bubbles, which in turn decreases the efficiency of vertical mixing.