Morphological classification of low viscosity drop bag breakup in a continuous air jet stream

To investigate the effect of Rayleigh–Taylor wave number in the region of maximum cross stream dimension (NRT) on drop breakup morphology, the breakup properties of accelerating low viscosity liquid drops (water and ethanol drops, diameter=1.2–6.6 mm, Weber number=10–80) were investigated using high-speed digital photography. The results of morphological analysis show a good correlation of the observed breakup type with NRT; bag breakup occurred when NRT was 1/3−1, bag-stamen breakup at 1–2, and dual-bag breakup at 2–3. The number of nodes in bag breakup, bag-stamen breakup, and dual-bag breakup all increased with Weber number. The experimental results are consistent with the model estimates and in good agreement with those reported in the literature.