Atomization by jet impact
Résumé
The formation and fragmentation of liquid sheets resulting from the oblique collision of two identical cylindrical jets is investigated. The liquid expands radially from the impacting point forming a sheet in the form of a bay leaf bounded by a thicker rim. The sheet shape, rim size and liquid velocity field are quantified and represented analytically. External harmonic perturbations of the injection conditions reveal the nature of the rim destabilization and of its coupling with the sheet. Flow perturbations in the incident jets lead to sheet thickness modulations which trigger the fragmentation of the rim via the formation of liquid ligaments whose dynamics is described. The breakup of these ligaments induce both the shape and width of the drop size distribution in the spray formed by this process.