Simulation of hindered settling in bidisperse suspensions of rigid spheres Original Research Article

We use a recently developed algorithm to simulate and study the physics of bidisperse suspensions of rigid spheres. We compute the settling velocity as a function of the ratio λ≡aL/aS≥1 of the radius of the large aL and small aS particles at a solid volume fraction of φ=0.14 and compare our results to predictions of the theory by Batchelor and a semi-analytical formula by Davis and Gecol. None of these predictions agree well with our findings, but the Davis and Gecol form seems to capture some aspects of the physics in the semi-dilute regime more accurately.