Higuera F J
ETS Ingenieros Aeronáuticos, Plaza Cardenal Cisneros 3, 28040 Madrid, Spain.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Jul;68(1 Pt 2):016304. doi: 10.1103/PhysRevE.68.016304. Epub 2003 Jul 14.
An analysis is carried out of the electric field-induced evaporation of ions from the surface of a polar liquid that is being electrosprayed in a vacuum. The high-field cone-to-jet transition region of the electrospray, where ion evaporation occurs, is studied taking advantage of its small size and neglecting the inertia of the liquid and the space charge around the liquid. Evaporated ions and charged drops coexist in a range of flow rates, which is investigated numerically. The structure of the cone-to-jet transition comprises: a hydrodynamic region where the nearly equipotential surface of the liquid departs from a Taylor cone and becomes a jet; a slender region where the radius of the jet decreases and the electric field increases while the pressure and the viscous stress balance the electric stress at the surface; the ion evaporation region of high, nearly constant field; and a charged, continuously strained jet that will eventually break into drops. Estimates of the ion and drop contributions to the total, conduction-limited current show that the first of these contributions dominates for small flow rates, while most of the mass is still carried by the drops.
对在真空中进行电喷雾的极性液体表面离子的电场诱导蒸发进行了分析。利用电喷雾的高场锥-射流过渡区域尺寸小这一特点，并忽略液体的惯性和液体周围的空间电荷，对发生离子蒸发的该区域进行了研究。在一定流速范围内，蒸发离子和带电液滴共存，对此进行了数值研究。锥-射流过渡区的结构包括：一个流体动力学区域，液体的近等势面从泰勒锥偏离并变成射流；一个细长区域，射流半径减小，电场增加，同时压力和粘性应力在表面平衡电应力；高的、近乎恒定场强的离子蒸发区域；以及最终会破碎成液滴的带电、持续受应变的射流。对离子和液滴对总传导受限电流的贡献估计表明，对于小流速，这些贡献中的第一个占主导，而大部分质量仍由液滴携带。
