Transition of breakup modes for a liquid jet in a static electric field

Takao Yoshinag ； Takasumi Iwai

《Proceedings of the Estonian Academy of Sciences》 64卷3S期 (2015/09) Pp. 449-456

https://doi.org/10.3176/proc.2015.3S.16

並列摘要

We analytically investigate breakup phenomena of a viscous liquid column jet closely placed in a concentric sheath on which a static electric field is imposed. Taking account of a surrounding electric field of the jet, long wave nonlinear equations of the jet radius, velocity, and electric surface charge density are derived. These equations are numerically solved for the initialboundary condition that a semi-spherical jet initially emanates from a nozzle exit. It is shown that there exist three types of breakup modes - jetting, spraying, and spinning -depending upon the parameters Λ (electric force/fluid inertial force) and Pe (convective current/conductive current). Then, critical curves are found in the Λ- Pe parameter space, across which the mode is transferred from the jetting to the spinning through the spraying with the increase of Λ and/or the decrease of Pe. In the transition from jetting to spraying mode, the produced drop size gradually decreases with the increase of Λ for larger Pe. On the other hand, there is a range of Λ where the drop size discontinuously decreases with increasing L for smaller Pe, which may lead to producing a satellite drop.

並列關鍵字

liquid jet ； electric field ； instability ； electro-spraying ； electro-spinning