2015/08/18 by Eliezer Keinan, Keinan, Eliezer, Ezra, Elishai +2
Engineering · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Granular flow and fluidized beds #Microfluidic and Bio-sensing Technologies #Particle Dynamics in Fluid Flows
paper · pdf · doi:10.48550/arxiv.1508.04305
openalex publication_date 2015/08/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Inertial focusing is the migration of particles in fluid toward equilibrium,\nwhere current theory predicts that shear-induced and wall-induced lift forces\nare balanced. First reported in 1961, this Segre-Silberberg effect is\nparticularly useful for microfluidic isolation of cells and particles.\nInterestingly, recent work demonstrated particle focusing at high Reynolds\nnumbers that cannot be explained by current theory. In this work, we show that\nnon-monotonous velocity profiles, such as those developed in curved channels,\ncreate peripheral velocity maxima around which opposing shear-induced forces\ndominate over wall effects. Similarly, entry effects amplified in high Reynolds\nflow produce an equivalent trapping mechanism in short, straight channels. This\nnew focusing mechanism in the developing flow regime enables a 10-fold\nminiaturization of inertial focusing devices, while our model corrects\nlong-standing misconceptions about the nature of mechanical forces governing\ninertial focusing in curved channels.\n