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Partial slip boundary conditions for collisional granular flows at flat frictional walls
Author(s) -
Yang Lei,
Padding J. T.,
Kuipers J. A. M.
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15534
Subject(s) - mechanics , granular material , kinetic theory , dissipation , boundary value problem , physics , cauchy stress tensor , spheres , slip (aerodynamics) , kinetic energy , particle (ecology) , periodic boundary conditions , classical mechanics , rotation (mathematics) , materials science , thermodynamics , geometry , mathematics , geology , oceanography , quantum mechanics , astronomy
We derive new boundary conditions (BCs) for collisional granular flows of spheres at flat frictional walls. A new theory is proposed for the solids stress tensor, translational and rotational energy dissipation rate per unit area and fluxes of translational and rotational fluctuation energy. In the theory we distinguish between sliding and sticking collisions and include particle rotation. The predictions are compared with literature results obtained from a discrete particle model evaluated at a given ratio of rotational to translational granular temperature. We find that the new theory is in better agreement with the observed stress ratios and heat fluxes than previous kinetic theory predictions. Finally, we carry out two fluid model simulations of a bubbling fluidized bed with the new BCs, and compare the simulation results with those obtained from discrete particle simulations. The comparison reveals that the new BCs are better capable of predicting solids axial velocity profiles, solids distribution near the walls and granular temperatures. © 2016 American Institute of Chemical Engineers AIChE J , 63: 1853–1871, 2017