The spatial-temporal instability behavior of an electrified viscoelastic liquid sheet

Abstract

The spatial-temporal instability of an electrified viscoelastic liquid sheet injected into air in a vertical electric field is analysed, in which the complete electrical force is considered. A new mode induced by the electric field (referred to as electrical mode) is found in the long wave region. The results show that the absolute-convective instability (AI-CI) of the electrical mode is only affected by the electric field, while that of the hydrodynamic mode is significantly influenced only when the electric field exceeds a threshold value. In most cases, the electrical mode is the dominant mode unless the Euler number is very small or large. The dominant mode first transforms from the hydrodynamic mode to the electrical mode in a weak electric field, when the flow is convectively unstable. However, it would change back in absolute instability region with a strong electric field. In addition, the competition between the two modes is also influenced by the Weber number and Reynolds number.