Investigation on the influence of vortex generator on particle resuspension

Abstract

The vortex generator (VG) and its well-known effect in flow optimization are widely studied and employed across different engineering sectors. However, while the same working principles of VG may be well suited for the applications on surface-cleaning technologies, such promising potential is hardly, if any, explored in the published literature. Therefore, in the present study, the influence on flow-induced particle resuspension brought by a rectangular VG in a channel flow is investigated with the help of high-fidelity computational fluid dynamics simulations. Substantial increases of particle removal forces and resuspension rates are discovered in long, strip-like regions with reduced boundary-layer thickness resulted from the VG-induced vortices, and the enhancement effect is especially significant for configurations with the VG installed at a greater angle of attack. It is also shown that while the resuspension enhancements on the lower and the upper surfaces of the channel exhibit distinct statistical characteristics, having a VG in the channel improves the overall particle-removing capability of the channel flow by introducing higher surface-averaged removal forces and particle resuspension rates. Last but not least, the increase of resuspension rate is especially significant for the smaller, micron-scale particles which are otherwise hardly disturbed by a VG-less channel flow, and such resuspension-enhancement effect generally subsides with increasing particle size.