Influence of Gas Flow on Plasma Length in Atmospheric Pressure Plasma Jet
Influence of Gas Flow on Plasma Length in Atmospheric Pressure Plasma Jet
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DOI：
10.7566/jpscp.1.015084
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发表时间：
2014-03
期刊：
影响因子：
--
通讯作者：
K. Yambe;T. Furuichi;K. Ogura
中科院分区：
文献类型：
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作者：
K. Yambe;T. Furuichi;K. Ogura
近年来，大气压环境下的等离子体技术已被应用于工业、医疗和生物领域。大气压等离子体，例如等离子射流，通常使用弧光放电和介质阻挡放电(DBD)来产生。DBD的大气压等离子体是用石英管作为介质、稀有气体和金属电极，通过施加射频和高压间歇产生的。等离子体喷流被释放到大气中，是一种小体积的子弹状的等离子体，以异常高的速度运动。等离子体行进的长度影响气体流动[2]。气体流动可概括为层流、过渡和湍流三种模式。在这项工作中，我们考察了等离子体行进长度与气体流量的关系。等离子体长度与气体流量的关系以及各模式下的等离子体形状如图1所示。在这种构型中，层流模式是小于6SLM的区域，湍流模式是大于10SLM的区域。发现有3例等离子体射流尖端受到扰动。因此，等离子体射流尖端的雷诺数随着截面上氦比的减小而增大。
Recently, plasma techniques under atmospheric pressure circumstances have been adapted for industrial, medical and biological applications. Atmospheric pressure plasmas, such as a plasma jet are typically produced using an arc discharge and a dielectric barrier discharge (DBD). Atmospheric pressure plasma of DBD is intermittently generated using a quartz tube as a dielectric, rare gas and metal electrode by applying radio frequency and high voltage [1]. A plasma jet is released to the atmosphere and is a small bullet-like volume of plasma traveling at unusually high velocities. The length of plasma traveling influences a gas flow [2]. The gas flow is summarized in a laminar, transition and turbulent modes. In this work, we examine the dependence of length of plasma traveling on the gas flow rate. The dependence of plasma length on gas flow rate and the pictures of plasma shape in each mode are shown in Fig. 1. In this configuration, the laminar mode is the region of less than 6 slm and the turbulent mode is the region of more than 10 slm. It is found that the tip of plasma jet in three cases is disturbed. Therefore, the Reynolds number at the tip of plasma jet increases due to the decrease of helium ratio on the cross-section.