Numerical investigation of particulate flow behavior in particle-wall impaction

The mean behavior of particulate flow in the vicinity of a wall, comprising both incident and reflected particles resulting from the process of partic le-wall impaction, is studied using a Lagrangian approach. The influence of the incident and reflected particles on the mean behavior of particulate f low is investigated by separating the different contributions from these tw o groups of particles. From the Lagrangian simulation, a particle-rebound d istance is identified within which the mean behavior of particulate flow ha s been significantly modified due to the process of particle-wall impaction . It is found that this particle rebound distance is dependent on Stokes nu mber (particle inertia), fluid Reynolds number (fluid flow condition), and restitution coefficients (particle-wall impaction). One finding from this s tudy is that the mean particulate velocity normal to the wall within the pa rticle-rebound distance is suddenly decreased by the negative contribution from the reflected particles. Another finding of significant interest is th at the mean particulate concentration near the edge of the particle-rebound distance has a significantly high value because of the slowing down motion of the reflected particles. It is also found that the main contribution to this change of mean behavior of particulate flow is due to the reflected p articles and thereafter multiple impacts.