Numerical calculation of the particle–fluid–particle stress in random arrays of fixed particles

The phase interaction force in a multiphase flow is decomposed into a particle-mean field force and a divergence of a Particle-Fluid-Particle (PFP) stress. The particle mean field force is mainly accounted for through drag models, while the PFP stress arising from the interparticle interactions is seldom reported. Using the nearest particle statistics, the PFP stress is calculated from particle-resolved simulations. The PFP stress represents the macroscopic effect of the drafting-kissing-tumbling mechanism.