Fluid-particle drag force measurements from particle-resolved CFD simulations of flow past random arrays of ellipsoidal particles

The lack of constitutive drag laws for non-spherical particles represents a current gap in simulating fluidparticle flows, even though such non-spherical shapes are encountered in numerous applications. Some previous studies have applied spherical drag models to non-spherical particles, while others have used ad-hoc methods to account for particle shapes. However, the present work demonstrates the need to develop dedicated non-spherical drag laws, given the limitations of these previous ad-hoc approaches. In the present study, single-phase computational fluid dynamics (CFD) simulations of fluid flow over random arrays of ellipsoids are used to directly calculate the fluid-particle drag forces. By varying the particle shape, orientation, solid fraction, and fluid-flow velocity (Reynolds number), this work probes the variables that would be important for future model development. A preliminary non-spherical drag model is proposed based on the CFD results, which illustrates the functional dependency of the non-spherical drag on particle aspect ratio and orientation. (c) 2021 Published by Elsevier Ltd.

Automated summary

The lack of constitutive drag laws for non-spherical particles in fluid-particle flows highlights the need for dedicated laws to replace previous ad-hoc methods. Computational fluid dynamics simulations were used to explore important variables for future model development and propose a preliminary non-spherical drag model based on the results.