Mode transitions in an oscillating liquid sheet

Longitudinal oscillations in air-blasted or air-assisted liquid sheets have been the subject of a large number of papers in the last 30 years. Frequency and sometimes amplitude are the main parameters used to characterize these oscillations. Attending to them, and also in dependence on the surface topology (e.g., the presence of perforations or ligaments), several oscillation modes have been described. In most works, two or at most three regimes are considered. Following these previous descriptions, this experimental work has found that some submodes can also be discerned. Based on visual observations, frequency measurements, and spray angle calculations, for some liquid and air flow rates up to six modes have been observed with defined transitions among them. The different modes are analyzed and characterized, and their presence is related to the flow conditions. © 2011 American Institute of Physics.Peer Reviewe