On Energy Budget and Turbulence Investigations in Particle-Driven Gravity Currents with High-Resolution Simulations

Abstract

For this work, we are interested in the prediction of a mono-disperse dilute suspension particle-laden flow in the typical lock-exchange configuration using Direct Numerical Simulation (DNS).
The main objective of this theoretical and numerical study is to undertake unprecedented simulations in order to focus on the energy budget of the flow and the turbulence characteristics for a range Reynolds number from 2236 up to 10000. For the lower Re case we also consider the density-driven current, that is, without deposition. The energy budget based on governing equations is developed enabling to investigate the full balance between kinetic and potential energy with dissipation terms (due to advective fluid motion and Stokes flow around particles). Also the main features of the flow are presented such as: the temporal evolution of the front location, the sedimentation rate, the resulting streamwise deposit profiles and the shear velocity at the bottom of the channel. The use of Direct Numerical Simulation allows us to investigate the evolution of turbulent structures at the wall, identifying the lobe-and-cleft patterns on the lead of the currents.