Siarhei Khirevich

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Time and length scales as well as the magnitude of individual contributions to eddy dispersion in chromatographic beds are resolved. We address this issue by a high-resolution numerical analysis of flow and mass transport in computer-generated bulk (unconfined) packings of monosized, nonporous, incompressible, spherical particles and complementary confined(More)
Flow and transport in a particle-packed microchip separation channel were investigated with quantitative numerical analysis methods, comprising the generation of confined, polydisperse sphere packings by a modified Jodrey-Tory algorithm, 3D velocity field calculations by the lattice-Boltzmann method, and modeling of convective-diffusive mass transport with(More)
The three-dimensional velocity field and corresponding hydrodynamic dispersion in pressure-driven flow through fixed beds of solid (impermeable), uniformly sized, spherical particles are studied by quantitative numerical analysis for conduits with different cross-sectional geometries. Packings with average interparticle porosities (bed porosities) of 0.40 <(More)
We study the time and length scales of hydrodynamic dispersion in confined monodisperse sphere packings as a function of the conduit geometry. By a modified Jodrey-Tory algorithm, we generated packings at a bed porosity (interstitial void fraction) of ε=0.40 in conduits with circular, rectangular, or semicircular cross section of area 100πd(p)(2) (where(More)
The mass transport properties of bulk random sphere packings depend primarily on the bed (external) porosity ε, but also on the packing microstructure. We investigate the influence of the packing microstructure on the diffusive tortuosity τ=D(m)/D(eff), which relates the bulk diffusion coefficient (D(m)) to the effective (asymptotic) diffusion coefficient(More)
The three-dimensional velocity field and corresponding hydrodynamic dispersion in electrokinetic flow through a random bulk packing of impermeable, nonconducting spheres are studied by quantitative numerical analysis. First, a fixed bed with interparticle porosity of 0.38 is generated using a parallel collective-rearrangement algorithm. Then, the(More)
This article investigates the efficiency of particulate beds confined in quadrilateral microchannels by analyzing the three-dimensional fluid flow velocity field and accompanying hydrodynamic dispersion with quantitative numerical simulation methods. Random-close packings of uniform, solid (impermeable), spherical particles of diameter d(p) were generated(More)
We present results of computer simulations of the effective diffusion coefficient in bulk random packings of hard monosized spheres with solid volume fraction between 0.54 (random-loose packing) and 0.634 (maximally random jammed). Six types of sphere packings were generated with different protocols and parameters resulting in a systematically varied degree(More)
The narrow particle size distribution (PSD) of certain packing materials has been linked to a reduced eddy dispersion contribution to band broadening in chromatographic columns. It is unclear if the influence of the PSD acts mostly on the stage of the packing process or if a narrow PSD provides an additional, intrinsic advantage to the column performance.(More)