LAUSR

Abstract Fluid forces and torques in a random stationary suspension of oblate cylinder-like particles of AR0.25 are investigated in the Reynolds number range 10 ≤ Re ≤ 300 and solid fraction range 0.1 ≤ φ ≤ 0.3 using Particle Resolved Simulations with the Immersed Boundary Method (IBM). While existing correlations were found to grossly under predict the drag forces, a sinusoidal function F d , θ = F d , θ = 0 ∘ + ( F d , θ = 90 ∘ − F d , θ = 0 ∘ ) sin ( θ ) captured the variation of normalized drag with respect to inclination angle over the range 10 ≤ Re ≤ 300 and 0 ≤ φ ≤ 0.3. Further the mean ensemble drag followed F d = F d , θ = 0 ∘ + 1 2 ( F d , θ = 90 ∘ − F d , θ = 0 ∘ ) . Lift forces varied between 20% and 80% of drag forces over the range of Reynolds numbers studied. Comparing the pitching fluid torque to collision torque in an elastic collision showed that as the particle equivalent diameter, density, and collision velocity decrease, fluid torque can be of the same order of magnitude as collisional torque and cannot be neglected.