Observation of particles behavior near the wall using a narrow channel

Abstract

Particle behavior on flat plate in narrow flow channel was experimentally investigated. As the test particle, polystyrene particle, glass particle, TiO2 and SiO2 powder were used and compared differences in behaviors for each particle. Number density of particles was measured using the microscope camera. Relatively large particles were removed from the wall surface to upper layer of the flow by the effect of lift force. However, the small and high density particles such as the TiO2 powder, could not remove from the wall surface. In addition, the difference in particle velocity for each particle diameter in a steady flow was measured using polystyrene at near the wall surface and center of narrow flow channel. At near the wall surface, large particles trended to move faster than small particles. At center of narrow flow channel, particle velocity was constant regardless of particle diameter. At near the wall surface, large particles was affected by the velocity distribution by shear layer and move faster than small particles.