A novel approach for separation of inertial particles*

In this work, we study the segregation of inertial particles of different size in spatially and temporally varying flows. At first, we focus on flows with spatially uniform velocity gradient tensor but with time-harmonic amplitudes. The clustering or mixing behavior of particles in these flows is strongly governed by particle density and size. Specifically, it has been shown that under certain conditions, clustering occurs over a highly narrow band of Stokes number (Esmaily-Moghadam and Mani, 2017, arXiv:1704.00370). This study aims to analyze design concepts that utilize this phenomenon for precise separation applications. We present three performance measures that help assess these devices: a separation resolution, a minimum device size requirement, and a measure of robustness to perturbations (e.g., due to particle collisions). Furthermore, by extending the design space to systems involving periodic but non-harmonic signals, we develop key guidelines for the design of such separation devices.