2023/06/17 by Varun Kulkarni, Kulkarni, Varun
Agricultural and Biological Sciences · Engineering · #Electrohydrodynamics and Fluid Dynamics #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Heat Transfer #Laser-induced spectroscopy and plasma #Mathematical Physics (math-ph) #Plant Surface Properties and Treatments
paper · pdf · doi:10.48550/arxiv.2306.10421
openalex publication_date 2023/06/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Bag breakup of drops has been a subject of interest for almost over a\ncentury. Several issues such as theoretical estimation of the regime boundary\nmarking the onset of such breakup, bag growth rates, drop size distribution,\nand the effect of Weber number, We, and Ohnesorge number, Oh, on these\nquantities remains unaddressed. The current study aims to clarify aspects of\nthe atomization process through experiments and theory. We examine bag breakup\nof a single drop of various inviscid and low viscosity fluids as it deforms in\nthe presence of a continuous horizontal air jet. The We boundary at which bag\nbreakup begins is theoretically determined and the expression obtained, We =\n12(1 + \(2)/(3) Oh2), is found to match well with existing experimental\ndata. An exponential growth in the radial extent of the deformed drop and the\nstreamline dimension of the bag is predicted by the theoretical model and\nconfirmed by experimental findings. These quantities are observed to strongly\ndepend on We. However, their dependence on Oh is weak for the range of Oh\nconsidered in this study. Subsequent to drop deformation, bag formation and\nexpansion is the bursting process. This is marked by the disintegration of the\nbag owing to instability of the Rayleigh-Taylor type, followed by collapse of\nthe liquid rim bounding this bag by Plateau-Rayleigh instability. The sizes of\nthe drops thus produced are measured using Phase Doppler Anemometry (PDA) which\nis in contrast to shadowgraphs used in earlier studies. A discernible shift in\nthe peak of the drop size distribution for viscous drops is seen which\nindicates a preponderance of drops of higher diameters vis- `a-vis fragment\nsize distribution for inviscid drops. Furthermore, an estimate of the Sauter\nmean diameter (D32) is presented which is somewhat lower than earlier\npredictions.\n