Assessment of behavioral modification techniques through immersed boundary method simulation of binary particle interactions in isotropic turbulence

Abstract

Behavioral modification effects for particle-laden turbulent flows are developed and assessed through high-fidelity modeling using an implementation of the mirroring ghost-cell based immersed boundary method in conjunction with direct numerical simulation. The continuous phase uses the open-source spectral element method-based solver, Nek5000. A dynamic form of the mirroring immersed boundary method is described that also solves for interparticle attraction and repulsion forces allowing for nontrivial collision outcomes such as agglomeration. The solid-phase solver is validated against empirical drag coefficient data as well as spherical bouncing experiments with excellent agreement obtained at low particle Reynolds numbers. Periodic boxes of homogeneous isotropic turbulence are generated using the linear forcing method at Reλ=29, 51, and 120. Ensembles of structure-resolved binary particle collisions are then studied within these boxes, considering the variation of six key mechanical and chemical parameters. These are the coefficient of restitution, Hamaker constant, surface charge potential, inverse Debye length, temperature, and Reynolds number. It is established that the coefficient of restitution, inverse Debye length, and Reynolds number have the greatest impact on the resulting particle motion and interaction by considering probability density functions of intersurfacial distance and relative particle velocities. Suggestions for real-world procedures that modify these parameters in order to either encourage or discourage particle interaction and potential agglomeration are discussed.