1. Multiscale Modeling of Flood-Induced Surface Erosion in a Particle Bed
Yasser Abdelhamid
Advisor: Dr. Usama El Shamy
Department of Civil and Environmental Engineering
Southern Methodist University, Dallas, TX 75275

2. Introduction
Experimental observations show that if the fluid flow velocity exceeds a certain value, the particles in the upper layers of the bed would start moving (sheetflow).
Surface erosion is a particle level phenomenon and therefore, a numerical model that is capable of tracking the behavior of the particle bed at microscale is needed.
Sheetflow Layer
Stationary Bed
1) Sheetflow mechanism. 2) The microscale effect.

3. Coupled Fluid-Particle Model
Using a microscale model that can model both phases at microscale level
Fluid velocity inside the soil pores

4. Coupled Fluid-Particle Model
Discrete solid phase:
Newton’s second law of motion:
Fluid phase:
The equation that describes the collision and streaming in a timestep:
Linear momentum
Angular momentum
Using a microscale model that can model both phases at microscale level
Fluid velocity inside the soil pores
D2Q9 model

5. Particle Bed Simulations
Highlight that the initial bed y=0

6. Particle Bed Erosion U=2.0 m/s
1) Sheetflow then lift and leave the particle particle bed +erosion takes place (layer by layer)