Print Email Facebook Twitter Effect of microchannel structure and fluid properties on non-inertial particle migration Title Effect of microchannel structure and fluid properties on non-inertial particle migration Author Maitri, R. V. (Eindhoven University of Technology) De, S. (Eindhoven University of Technology; Shell) Koesen, S. P. (Eindhoven University of Technology) Wyss, H. M. (Eindhoven University of Technology) van der Schaaf, J. (Eindhoven University of Technology) Kuipers, J. A.M. (Eindhoven University of Technology) Padding, J.T. (TU Delft Complex Fluid Processing; TU Delft Intensified Reaction and Separation Systems) Peters, E.A.J.F. (Eindhoven University of Technology) Date 2019 Abstract In this work, we investigate the influence of channel structure and fluid rheology on non-inertial migration of non-Brownian polystyrene beads. Particle migration in this regime can be found in biomedical, chemical, environmental and geological applications. However, the effect of fluid rheology on particle migration in porous media remains to be clearly understood. Here, we isolate the effects of elasticity and shear thinning by comparing a Newtonian fluid, a purely elastic (Boger) fluid, and a shear-thinning elastic fluid. To mimic the complexity of geometries in real-world application, a random porous structure is created through a disordered arrangement of cylindrical pillars in the microchannel. Experiments are repeated in an empty channel and in channels with an ordered arrangement of pillars, and the similarities and differences in the observed particle focusing are analyzed. It is found that elasticity drives the particles away from the channel walls in an empty microchannel. Notably, particle focusing is unaffected by curved streamlines in an ordered porous microchannel and particles stay away from pillars in elastic fluids. Shear-thinning is found to reduce the effect of focusing and a broader region of particle concentration is observed. It is also noteworthy that the rheological characteristics of the fluid are not important for the particle distribution in a randomly arranged pillared microchannel and particles have a uniform distribution for all suspending fluids. Moreover, discussion on the current discrepancy in the literature about the equilibrium positions of the particles in a channel is extended by analyzing the results obtained in the current experiments. To reference this document use: http://resolver.tudelft.nl/uuid:0e8edd8b-55cc-4b4e-a178-0d3bf09d0569 DOI https://doi.org/10.1039/c8sm02348d ISSN 1744-683X Source Soft Matter, 15 (12), 2648-2656 Part of collection Institutional Repository Document type journal article Rights © 2019 R. V. Maitri, S. De, S. P. Koesen, H. M. Wyss, J. van der Schaaf, J. A.M. Kuipers, J.T. Padding, E.A.J.F. Peters Files PDF c8sm02348d.pdf 3.82 MB Close viewer /islandora/object/uuid:0e8edd8b-55cc-4b4e-a178-0d3bf09d0569/datastream/OBJ/view