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Fluid‐particle drag in low‐Reynolds‐number polydisperse gas–solid suspensions
Author(s) -
Yin Xiaolong,
Sundaresan Sankaran
Publication year - 2009
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.11800
Subject(s) - drag , reynolds number , particle (ecology) , drag coefficient , drag equation , mechanics , lattice boltzmann methods , particle size , suspension (topology) , volume fraction , parasitic drag , thermodynamics , chemistry , classical mechanics , physics , turbulence , mathematics , geology , drag divergence mach number , oceanography , homotopy , pure mathematics
Lattice‐Boltzmann simulations of low‐Reynolds‐number fluid flow in bidisperse fixed beds and suspensions with particle–particle relative motions have been performed. The particles are spherical and are intimately mixed. The total volume fraction of the suspension was varied between 0.1 and 0.4, the volume fraction ratio ϕ 1 /ϕ 2 from 1:1 to 1:6, and the particle size ratio d 1 / d 2 from 1:1.5 to 1:4. A drag law with improved accuracy has been established for bidisperse fixed beds. For suspensions with particle–particle relative motions, the hydrodynamic particle–particle drag representing the momentum transfer between particle species through hydrodynamic interaction is found to be an important contribution to the net fluid‐particle drag. It has a logarithmic dependence on the lubrication cutoff distance and can be fit as the harmonic mean of the drag forces in bidisperse fixed beds. The proposed drag laws for bidisperse fixed beds and suspensions are generalized to polydisperse suspensions with three or more particle species. © 2009 American Institute of Chemical Engineers AIChE J, 2009