Numerical simulations of the separation of elastic particles in a T-shaped bifurcation

In this work, we study the dynamics of an elastic particle suspended in an inertialess Newtonian fluid flowing through a channel with an orthogonal side branch (asymmetric T-shaped bifurcation) by means of 2D Arbitrary Lagrangian Eulerian (ALE) Finite Element Method (FEM) direct numerical simulations. The simulations show that, when the fluid is equally partitioned in the two downstream branches and the particle starts from the inflow channel centerline, a sufficiently deformable particle is deviated into the ‘side’ branch, at variance with a rigid particle, which remains in the ‘main’ outlet. The effects of the elastic capillary number and the confinement ratio on the particle trajectory and deformation near the bifurcation are investigated. We discuss how this device can be exploited for separating particles based on their elasticity.