Simulating particulate flow through curved duct by comparing tangential and normal velocities

Particles, especially nano- And micro-particles, generated by combustion disperse in the air and form aerosol contaminants (e.g. PM10), which will affect human health and the living environment severely. This paper studies particle flow behavior including tangential and normal velocities in the curved duct in order to understand particle transportation for contaminant control. Computational Fluid Dynamics (CFD) tools together with user defined model were utilized. Through numerical analysis and modeling, it is found that the predicted particle tangential velocities can reach up to 1.3 times of bulk velocity at certain locations. They accelerate near the inner wall while decelerate near the outer wall. In contrast, particle normal velocities are only up to 0.17 of bulk velocity. They fluctuate more obviously than tangential velocity profile partly due to particle and wall materials and their interaction. The material effect mainly affects particle wall interaction, deposition, rebounding, and near wall velocities.