Monodisperse microbubbling:: Absolute instabilities in coflowing gas-liquid jets

Contrary to liquid jets, gas jets in coflowing liquid streams are highly unstable. When these gas jets are sufficiently small, their breakup into microbubbles is strongly self-locked at a certain frequency. This provokes a continuous streaming of microbubbles with perfectly homogeneous and controllable size. In this work, we describe theoretically the absolute instability origin of the dynamical behavior of these gas jets surrounded by a coflowing liquid stream, and give the explanation to the extremely elusive nature of a gas ligament. (C) 2001 American Institute of Physics.