Study of particle dynamic resuspension in a recirculation flow using large-eddy simulations

Particle resuspension in the recirculation flow is a significant phenomenon in many industrial applications. This paper elaborated on particle resuspension including incipient motion, wall migration, and re-entrainment in the recirculation vortices of periodic semicircular obstructions, wherein particle incipient motion is predicted by the Rock'n'Roll model while the coupling between fluid and particles is calculated by Large-Eddy Simulation (LES) and Euler-Lagrange method. The results show that an upward instantaneous flow and enough friction velocity are essential for particle resuspension. Small particles are easily re-entrained into the primary vortex and then entered into the mainstream flow. In addition, particles entering the primary vortex of the recirculation region may return to the wall to produce the recycle resuspension. Compared with straight duct, the recirculation flow on particle resuspension greatly reduces the fraction of short-term resuspension particles, but the inhibition ability gradually decreases with time elapsing.