• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Physics, D. Applied Physics: A Europhysics Journal >Enthalpy probe measurements and three-dimensional modelling on air plasma jets generated by a non-transferred plasma torch with hollow electrodes
【24h】

Enthalpy probe measurements and three-dimensional modelling on air plasma jets generated by a non-transferred plasma torch with hollow electrodes

机译：带有空心电极的非转移等离子体炬产生的空气等离子体射流的焓探针测量和三维建模

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Thermal flow characteristics of air plasma jets generated by a non-transferred plasma torch with hollow electrodes are experimentally and numerically investigated in order to provide more reliable scientific and technical information, which has been insufficient for their practical applications to material and environmental industries. In this work, a thermal plasma torch of hollow electrode type is first designed and fabricated, and similarity criteria for predicting operational conditions for the scale-up to high-power torches are derived from the arc voltage characteristics measured with various operating and geometry conditions of the torch. The thermal flow characteristics of air plasma jets ejected from the torch are measured by enthalpy probe diagnostics and turn out to have relatively low temperatures of around 3000-7000 K, but show features of other unique properties, such as high energy flux, broad high temperature region and long plasma jet with moderate axial velocity, which are promising for their applications to material syntheses and hazardous waste treatments. Such high enthalpy at a relatively low temperature of air thermal plasma compared with the argon one is due to the high thermal energy residing in the vibrational and rotational states and oxygen dissociation, besides the translational states in monatomic gases such as argon. It is expected that this high specific enthalpy of the air plasma will enable material and environmental industries to treat a large amount of precursors and waste materials effectively at a lower temperature for a longer residence time by the low plasma velocity. It is also found from the measurements that the turbulence intensity influenced by the size of the electrode diameter has a significant effect on the axial and radial profiles of plasma jet properties and that a longer plasma jet is more readily achievable with a larger electrode diameter reducing the turbulence intensity in the external region of the torch. In the numerical studies based on magnetohydrodynamics (MHD) theory, a precise three-dimensional transient numerical model for the internal arc discharge plasma of the torch has been developed along with a practical two-dimensional stationary one for the external thermal plasma jet by considering highly localized distributions of arc roots with circumferential non-uniformity on the electrode wall surfaces, so that more reliable and realistic descriptions on the arc thermal plasma properties become feasible both inside and outside the torch. The numerical calculation results are compared with the experimental data obtained from the probe measurements and found to be in good agreement with them.
机译：为了提供更可靠的科学和技术信息，对具有空心电极的非转移式等离子炬产生的空气等离子体射流的热流特性进行了实验和数值研究，不足以用于材料和环境行业的实际应用。在这项工作中，首先设计和制造了空心电极型热等离子炬，并根据在各种工作和几何条件下测得的电弧电压特性，得出了用于预测放大到高功率炬的工作条件的相似性标准。火炬。从火炬喷出的空气等离子体射流的热流特性通过焓探头诊断进行了测量，结果显示温度相对较低，约为3000-7000 K，但显示出其他独特特性的特征，例如高能量通量，宽广的高温具有中等轴向速度的区域和长等离子射流，有望将其应用于材料合成和危险废物处理。与氩气相比，在相对较低的空气热等离子体温度下如此高的焓是由于存在于振动和旋转状态以及氧离解中的高热能，以及诸如氩等单原子气体中的平移状态。期望空气等离子体的这种高比焓将使材料和环境工业能够以较低的等离子体速度在较低的温度下有效地处理大量的前体和废料，从而具有更长的停留时间。从测量结果还可以发现，受电极直径大小影响的湍流强度对等离子流特性的轴向和径向分布有显着影响，并且较长的等离子流更容易获得，而较大的电极直径则减小了火炬外部区域的湍流强度。在基于磁流体动力学（MHD）理论的数值研究中，通过高度考虑，开发了用于炬内部电弧放电等离子体的精确三维瞬态数值模型，以及用于外部热等离子体射流的实用二维固定模型。在电极壁表面上具有圆周不均匀性的电弧根的局部分布，因此在焊炬内部和外部都可以对电弧热等离子体特性进行更可靠，更实际的描述。将数值计算结果与从探针测量获得的实验数据进行比较，发现与它们非常吻合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号