Absolute and convective instability of a coaxial viscous liquid jet under both axial and radial electric fields

The absolute and convective instability of a coaxial viscous liquid jet in both radial and axial electric fields is studied. The outer liquid is assumed to be conducting and to be the driving liquid. The governing equations are solved numerically as a generalized eigenvalue problem. The effects of the parameters on the instability of the axisymmetric para-sinuous and first non-axisymmetric modes are explored. Both the radial and axial electric fields exhibit great effect on the modes. The dominant regions of the modes are identified on distinct parameter planes. The study helps us predict the behaviors of jets in coaxial electrospraying and coaxial electrospinning.