Evaluation of drag correlations using particle resolved simulations of spheres and ellipsoids in assembly

Particle-resolved simulations are performed to study the momentum transfer in flow though fixed random assembly of non-spherical particles. Ellipsoidal particles with sphericity (ψ=0.887) are investigated in a periodic cubic domain to simulate an infinite assembly. The incompressible Navier-Stokes equations are solved using the Immersed Boundary Method (IBM). Pressure and viscous force on each particle are calculated based on the resolved flow field. Flow through an assembly of spherical particles is tested, and predicted drag forces are compared with previous particle resolved simulation results to validate the current framework. The assembly of ellipsoidal particles is simulated for solid fraction between 0.1 and 0.35 using 191 to 669 particles, respectively, at low to moderate Reynolds numbers (10≤Re≤200). The simulation results show that the drag force of ellipsoidal particles is 15% to 35% larger than equal volume spherical particles. Widely used drag force correlations are evaluated based on the current simulation results. The comparisons show that for ellipsoidal particles over the range of parameters investigated in the present study, the combination of Tenneti et al.'s correlation with Holzer's single non-spherical particle drag model has the best performance with an average difference of 7.15%. [Display omitted] •The drag force for assembly of spherical particles agrees well with past study.•A framework is developed to investigate non-spherical particles.•Drag force of ellipsoidal particle assemblies is 15% to 35% larger than spheres.•Correlations using particle orientation show best agreement with current results.•Combined Tenneti et al. and Holzer correlation has 7.15% average error.