Instability of rotating cylindrical jets

A mathematical treatment is given of the instability of rotating cylindrical jets under the action of the inertial effects of the jet and its surface tension. Three types of jet are considered: In general the viscosity of the liquid and the inertial effects of the surrounding air have been neglected except in two cases: From the calculations the following conclusions may be drawn. If the liquid viscosity and the inertial effects of the ambient air are neglected: If the inertial effects of the ambient air or the liquid viscosity are taken into account: