The effects of particle shape on inertial focusing

Abstract

This paper proposes a 2D particle inertial focusing model by the immersed boundary–lattice Boltzmann method (IB-LBM), aiming to study the effects of particle shapes on their focusing state. First, as the validation, we investigated the inertial focusing of circular particles and got consistent focus positions with other previous reports. Then, the inertial focusing of the circle, rectangle, ellipse, and capsule particles were studied in detail. The results revealed that the particle shapes significantly influence the focusing positions, self-rotation, and running speed. At a given Reynolds number, the circular particle has a minimum average distance to the pipe center in the focus state, then follows the elliptical, capsular, and rectangular particles. The elliptical particle’s self-rotation cycle is in approximately the cubed relation to the long-short axis ratio. Moreover, the rectangle particle runs fastest at the same Reynolds number, followed by capsule, ellipse, and circle particles. Our study and the above results can provide a significant reference for screening or separating particles with different shapes in microfluidic devices.

Lattice-Boltzmann Modelling for Inertial Particle Microfluidics Applications — A Tutorial Review

“…Single particle simulations have been used to understand the effect of particle shape on inertial migration. Several works have investigated channel flows with non-circular particles in 2D [114,[135][136][137][138] and non-spherical particles in 3D [70,139,140]. Investigations of rigid biconcave objects have shown that their tumbling rotation leads to an oscillation of the lateral positions that depends on the particle size and aspect ratio [135].…”