Dynamics of the Surface Growth Resulted from Sedimentation of Spheres in a Hele-Shaw Cell Containing a Low-Viscosity Fluid

Abstract

In this paper, we investigate the dynamics of surface growth resulting from sedimentation of spherical granular particles in a fluid environment, using experiments and simulations. In the experimental part, spherical polystyrene particles are poured down from the top of a vertical Hele-Shaw cell and form a 1+1-dimensional growing surface. The surface roughness is obtained from the images and the growth and roughness exponents are measured. In the numerical simulation part, the surface growth process is simulated using the Molecular Dynamics method, considering the interactions between the grains; and the exponents are calculated. In this method, unlike conventional simulation models, instead of a discrete deposition law, the dynamics of the individual particles throughout the process are obtained considering different forces acting on the particles. Finally, the simulation results are compared with the experiment, and we see a very good agreement between them. We find different values for the exponents using different methods, which indicates that the system is multi-affine and does not obey scaling laws of affine models.