Density scaling laws for the structure of granular deposits.
The structure of granular deposits growing by arriving particles is analyzed using three-dimensional on-lattice Monte Carlo modeling of convective-diffusive particle deposition. The deposit density profile rho(h) depends on the particle dynamics and becomes formed by three different regions: a denser near-wall region at the deposit bottom in contact with the original plain surface, a middle uniform region with constant mean density, and an open and lighter active-growth region at the deposit outer surface. Fitting expressions for rho(h) valid in each region are proposed, based on the known features of deposits formed in the two limiting cases: ballistic deposition and diffusion-limited deposition. Also, a composite expression for rho(h) fitting the density profile throughout the deposit is given. All these expressions are written in terms of a length scale l(Pe) dependent on the particle Péclet number, which provides the relative importance of the convective motion to the diffusive transport for the particle.
Rodríguez-Pérez
Daniel
D
Departamento de Fisica Matematica y de Fluidos, Facultad de Ciencias, UNED, Madrid, Spain. daniel@dfmf.uned.es
Castillo
Jose L
JL
Antoranz
J Carlos
JC