부산대학교 도서관

Air flow and particle motions by a suction nozzle with a circular cross-section are numerically investigated to understand the effect of several parameters on flow characteristics and particle behaviors. The parameters considered include nozzle moving speed, nozzle-to-floor distance, and particle diameter. Based on the particle trajectories, the particles are divided into three groups: particles sucked in by the flow approaching the nozzle, particles sucked in by the backflow after passing around the nozzle, and particles that are too far from the nozzle to be picked up. The particle suction efficiency increases as the nozzle speed decreases, irrespective of particle diameter. However, the suction rate shows particle-size-dependent behaviors, showing an optimal nozzle speed for the case of the large particle diameter. The nozzle-to-floor distance greatly influences the particle pickup efficiency, showing that an optimal value exists.