Experimental and Numerical Modeling of Surface Erosion

In this paper, we present experimental and numerical techniques capable of modeling the transient fluid-particle interaction encountered in surface erosion at a particle and pore-scale. The experimental program was carried out utilizing digital particle image velocimetry (DPIV) to measure pore-scale fluid velocity and direct imaging of particles was used to determine particle positions in a particle bed subjected to flow conditions. Direct measurement of the motion of the two phases under conditions of high particle fraction in the particle bed were attained by instantaneous discrimination between the fluid and particle phases, which were refractive-index matched to allow full-field measurements. A two-dimensional transient fully coupled fluid–particle numerical model was utilized to explore the fundamental mechanisms of flood-induced erosion. The fluid was modeled at a pore-scale level using the lattice Boltzmann method (LBM). The particles were modeled using the discrete element method (DEM). Simulations were conducted on beds of different particle diameters and subjected to different fluid velocities to get a better understanding of the dynamics of sheet-flow and bed erosion.