The transport dynamics of tens of micrometer-sized water droplets in RF atmospheric pressure glow discharges
The transport dynamics of tens of micrometer-sized water droplets in RF atmospheric pressure glow discharges
复制标题
射频大气压辉光放电中数十微米大小的水滴的输运动力学
DOI：
10.1088/1361-6595/acc54a
复制
发表时间：
2023
影响因子：
3.8
通讯作者：
J Bruggeman, Peter
中科院分区：
文献类型：
--
作者：
Nayak, Gaurav;Meyer, Mackenzie;Oinuma, Gaku;J Kushner, Mark;J Bruggeman, Peter
直径为几十微米的颗粒的充电已经在大气压下在例如静电除尘器的背景下被广泛研究，其中焦点是单极充电。大气压等离子体中粒子，特别是液滴的双极充电，受到的关注较少。液滴的等离子体活化对于水净化、肥料生产和材料合成是有意义的，所有这些都取决于液滴通过等离子体的传输，这又取决于它们的充电。在本文中，我们报告的水滴，几十微米的直径，通过大气压射频辉光放电持续在氦气中的气流进行的运输动力学。液滴以最小的蒸发通过等离子体，并且没有达到瑞利极限。在等离子体存在和不存在的情况下的液滴轨迹提供了对作用在液滴上的力的了解。使用三维流体模型和二维等离子体流体动力学模型的结果进行了分析的测量。我们发现，作为液滴进入和离开等离子体的运输动力学是由于差分充电的液滴在等离子体梯度的约束鞘等离子体。
Charging of particles having diameters of tens of microns has been extensively studied at atmospheric pressure in the context of, for example, electrostatic precipitators where the focus was on unipolar charging. The ambipolar charging of particles in atmospheric pressure plasmas, and of droplets in particular, has received less attention. The plasma activation of droplets is of interest for water purification, fertilizer production and materials synthesis, all of which depend on the transport of the droplets through the plasma, which in turn depends on their charging. In this paper, we report on the transport dynamics of water droplets, tens of microns in diameter, carried by the gas flow through an atmospheric pressure radiofrequency glow discharge sustained in helium. The droplets pass through the plasma with minimal evaporation and without reaching the Rayleigh limit. The droplet trajectory in the presence and absence of the plasma provides insights on the forces acting on the droplet. The measurements were analyzed using results from a three-dimensional fluid model and a two-dimensional plasma hydrodynamics model. We found that the transport dynamics as the droplet enters and leaves the plasma are due to differential charging of the droplet in the plasma gradients of the bounding sheaths to the plasma.