RT Journal Article
T1 Diffusion of impurities in a moderately dense confined granular gas
A1 Gómez González, Rubén
A1 Garzó, Vicente
A1 Brito López, Ricardo
A1 Soto, Rodrigo
AB Mass transport of impurities immersed in a confined quasi-two-dimensional moderately dense granular gas of inelastic hard spheres is studied. The effect of the confinement on granular particles is modeled through a collisional model (the so-called ∆-model) that includes an effective mechanism to transfer the kinetic energy injected by vibration in the vertical direction to the horizontal degrees of freedom of grains. The impurity can differ in mass, diameter, inelasticity, or the energy injection at collisions, compared to the gas particles. The Enskog–Lorentz kinetic equation for the impurities is solved via the Chapman–Enskog method to first order in spatial gradients for states close to the homogeneous steady state. As usual, the three diffusion transport coefficients for tracer particles in a mixture are given in terms of the solutions of a set of coupled linear integral equations which are solved by considering the lowest Sonine approximation. The theoretical predictions for the tracer diffusion coefficient (relating the mass flux with the gradient of the number density of tracer particles) are compared with both direct simulation Monte Carlo and molecular dynamics simulations. The agreement is in general good, except for strong inelasticity and/or large contrast of energy injection at tracer-gas collisions compared to gas-gas collisions. Finally, as an application of our results, the segregation problem induced by both a thermal gradient and gravity is exhaustively analyzed.
PB American Institute of Physics
SN 1070-6631
YR 2024
FD 2024-12
LK https://hdl.handle.net/20.500.14352/118142
UL https://hdl.handle.net/20.500.14352/118142
LA eng
NO Gómez González, R., Garzó, V., Brito, R., & Soto, R. (2024). Diffusion of impurities in a moderately dense confined granular gas. Physics of Fluids, 36(12), 123387. https://doi.org/10.1063/5.0245373
NO Grant No. 1220536Millennium Science Initiative Program NCN19_170  (ANID)
NO Agencia Estatal de Investigación (España)
NO Ministerio de Ciencia, Innovación y Universidades (España)
NO Fondo Nacional de Desarrollo Científico y Tecnológico (Chile)
NO Agencia Nacional de Investigación y Desarrollo (Chile)
DS Docta Complutense
RD 20 dic 2025