Impingement of unlike-doublet liquid jets with different surface tensions

Abstract

The effect of surface tension asymmetry on the atomization of unlike-doublet impinging jets was experimentally studied. Three typical features were identified, including wrinkled sheet edge, inner-sheet patch, and serrated bottom rim. The wrinkled sheet edge represents the propagation front of the Marangoni flow subsequent to rim encapsulation. The inner-sheet patch is caused by the through-plane mixing across the liquid sheet with uneven thickness and results in the occurrence of the serrated bottom rim. In the presence of these Marangoni-driven flow structures, the liquid sheet tends to be more unstable, and atomization is improved for unlike-doublet impinging jets, as the breakup length is reduced and smaller droplets are generated compared to like-doublet impinging jets.