CFD investigation on particle deposition in aligned and staggered ribbed duct air flows

This study investigated the effects of surface rib arrangements on particle deposition in two-dimensional ribbed duct air flows by CFD method. The turbulent duct air flows were simulated by Reynolds stress model (RSM) with UDF correction, and the particle motions were solved by discrete particle model (DPM). The surface ribs were arranged in aligned or staggered layouts. The air velocity profiles for both smooth and ribbed duct flows as well as the particle deposition velocity for smooth duct cases were all in good agreement with the relative literature data. The simulation results showed that the surface ribs with aligned arrangement have better performance on small particle deposition enhancement, compared with staggered surface ribs. Nevertheless, the large particle deposition rates are not enhanced obviously by both kinds of surface ribs. Considering the flow drag increase, the maximum particle deposition enhancement can reach 425 times for particles with 1 µm diameter. Finally, the mechanisms of particle deposition enhancement by aligned and staggered surface ribs were analyzed and discussed from the views of rib interception, deposition area increase, turbulent eddy capture and the flow passage width. Surface ribs with aligned arrangement are recommended to be applied in particle removal and air clean devices.