Electrohydrodynamics of charge separation in droplet-based ion sources with time-varying electrical and mechanical actuation.
Electrohydrodynamics of charge separation in droplet-based ion sources with time-varying electrical and mechanical actuation.
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DOI：
10.1016/j.jasms.2009.12.022
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发表时间：
2010-04
影响因子：
3.2
通讯作者：
Fedorov AG
中科院分区：
文献类型：
--
作者：
Forbes TP;Degertekin FL;Fedorov AG
通过计算分析和辅助实验研究了机械驱动液滴基离子源中的电荷输运和分离。建立了电流体动力学(EHD)和电荷迁移的第一性原理模型，并用FLUENT CFD软件对射流/液滴的形成过程进行了模拟。为了验证实验的有效性，我们模拟了细毛细管电喷涂的经典实验，特别是有限电导率流体的瞬时EHD锥射流形成和完全导电流体中的泰勒锥形成。该模型还被用于研究机械驱动液滴基离子源中液滴充电的微观物理，例如AMUSE(微机械超声电喷雾阵列)。在这里，AMUSE受到不同幅度和相位的直流和交流电场，相对于驱动液滴形成的时变机械力。对于直流充电的情况，每个液滴携带的电荷与外加电场大小之间呈线性关系，与以前报道的实验一致。对于交流充电情况，在时变的机械(驱动喷射)和电气(驱动电荷传输)信号中精心选择的相移允许在喷射时将所需极性的电荷量显著增加到液滴中。对娱乐离子源产生的电喷雾电流和每滴电荷进行了补充的实验测量，并支持对直流和交流充电情况的理论预测。理论模型和模拟工具为耦合电流体动力学和电荷输运的基础研究提供了通用和通用的分析框架。该模型还允许探索不同的结构和工作模式，以优化静电场和动电场和机械场下大气压电流体离子源中的电荷分离。
Charge transport and separation in mechanically-driven, droplet-based ion sources are investigated using computational analysis and supporting experiments. A first-principles model of electrohydrodynamics (EHD) and charge migration is formulated and implemented using FLUENT CFD software for jet/droplet formation. For validation, classical experiments of electrospraying from a thin capillary are simulated, specifically, the transient EHD cone-jet formation of a fluid with finite electrical conductivity, and the Taylor cone formation in a perfectly electrically-conducting fluid. The model is also used to investigate the microscopic physics of droplet charging in mechanically-driven droplet-based ion sources, such as AMUSE (Array of Micromachined UltraSonic Electrospray). Here, AMUSE is subject to DC and AC electric fields of varying amplitude and phase, with respect to a time-varying mechanical force driving the droplet formation. For the DC-charging case, a linear relationship is demonstrated between the charge carried by each droplet and an applied electric field magnitude, in agreement with previously reported experiments. For the AC-charging case, a judiciously-chosen phase-shift in the time-varying mechanical (driving ejection) and electrical (driving charge transport) signals allows for a significantly increased amount of charge, of desired polarity, to be pumped into a droplet upon ejection. Complementary experimental measurements of electrospray electrical current and charge-per-droplet, produced by the AMUSE ion source, are performed and support theoretical predictions for both DC and AC-charging cases. The theoretical model and simulation tools provide a versatile and general analytical framework for fundamental investigations of coupled electrohydrodynamics and charge transport. The model also allows for the exploration of different configurations and operating modes to optimize charge separation in atmospheric pressure electrohydrodynamic ion sources under static and dynamic electrical and mechanical fields.
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影响因子：
19.6
作者：
Collins, Robert T.;Jones, Jeremy J.;Basaran, Osman A.
通讯作者：
Basaran, Osman A.
影响因子：
7.4
作者：
Marginean, I;Parvin, L;Vertes, A
通讯作者：
Vertes, A
DOI：
10.1016/j.jasms.2009.05.006
发表时间：
2009-09-01
影响因子：
3.2
作者：
Forbes, Thomas P.;Dixon, R. Brent;Fedorov, Andrei G.
通讯作者：
Fedorov, Andrei G.
影响因子：
4.6
作者：
Meacham, JM;Varady, MJ;Fedorov, AG
通讯作者：
Fedorov, AG
影响因子：
1.6
作者：
Meacham, JM;Ejimofor, C;Fedorov, AG
通讯作者：
Fedorov, AG