Particle spacing and stability of initially staggered deformable particle trains migrating in a channel

Abstract

Abstract We investigated the inertial migration of deformable particles in a two-dimensional channel flow. This study analyzes the effects of the channel Reynolds number ($Re$), channel blockage ratio ($k$), particle number ($N_p$) and reduced bending modulus ($E_b$) on the formation of staggered particle trains. The results show that the stable normalized distance $d_{p_{eq}} / H$ between two staggered particles is influenced by $Re$, $k$ and $E_b$, where $H$ is the channel width. As $k$ increases or $E_b$ decreases, $d_{p_{eq}} / H$ decreases. The value of $d_{p_{eq}} / H$ initially increases and then decreases with the increase of $Re$; when $E_b$ is large and $k$ is small, $d_{p_{eq}} / H$ continuously increases with increasing $Re$. With the increase of $N_p$, the closely arranged staggered particle trains evolve into five distinct migration Regimes. We explain the conditions for the formation of each Regime and explore the mechanisms of their interconversion. The findings of this study contribute to a better understanding of the self-organization process of deformable particles in channel flow.