Modeling the Dense Spray Regime Using an Euler-Lagrange Approach With Volumetric Displacement Effects

Abstract: Modeling of a dense spray regime using an Euler-Lagrange approach is challenging because of local high volume loading. A cluster of droplets, that are assumed subgrid, can lead to locally low void fractions for the fluid phase. Under these conditions, spatio-temporal changes in the fluid volume fractions should be considered in an Euler-Lagrange, two-way coupling model. This leads to zero-Mach number, variable density governing equations. Using pressure-based solvers, this gives rise to a source term in the pressure Poisson equation and a non-divergence free velocity field. To test the validity and predictive capability of such an approach, a round jet laden with particles is investigated using Direct Numerical Simulation coupled with point-Particle based model and compared with available experimental data for a particulate turbulent round jet with $Re_j=5712$. Standard force closures including drag, lift, Magnus effect, pressure, added mass as well as viscous torque acting on each individual particle are employed in the Point-Particle based model. In addition, volume displacement effects due to the presence of solid particles or liquid droplets, which is commonly neglected in the standard two-way coupling, are taken into account in both continuity and inter-phase momentum transfer to accurately capture the underlying structure of particle-turbulence interactions. Prediction results are in well agreement with the corresponding experiment.