Capillary‐Based Microfluidics—Coflow, Flow‐Focusing, Electro‐Coflow, Drops, Jets, and Instabilities

Drops: the collapse of capillary jets.

The appearance of fluid filaments during the evolution of a viscous fluid jet is a commonly observed phenomenon. It is shown here that the break-up of such a jet subject to capillary forces is impossible through the collapse of a uniform filament.

Current-driven instabilities in astrophysical jets

Current-driven instabilities of force-free screw pinches are studied for a large variety of magnetic configurations by means of a global linear analysis in an ideal MHD framework. The magnetic pitch, P = rBz/Bφ, in particular its value on the axis, P0, essentially determines the growth rate of the fastest growing kink instability and allows to identify two regimes. In the large pitch regime, re...

Interplay between Kelvin-Helmholtz and urrent-driven instabilities in jets

Pressure- and magnetic shear-driven instabilities in rotating MHD jets

We derive new stability criteria for purely MHD instabilities in rotating jets, in the framework of the ballooning ordering expansion. Quite unexpectedly, they involve a term which is linear in the magnetic shear. This implies that cylindrical configurations can be destabilized by a negative magnetic shear as well as by a favorable equilibrium pressure gradient, in distinction with the predicti...

Oscillatory jets and instabilities in a rotating cylinder