Experimental Study on the Thermal Argon Plasma Generation and Jet Length Change Characteristics at Atmospheric Pressure

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• 作者：Wenxia Pan ; Xian Meng ; Chengkang Wu and Xi Chen
• 关键词：Thermal plasma ; Generating parameter ; Laminar jet ; Turbulent flow ; Jet ; length change
• 刊名：Plasma Chemistry and Plasma Processing
• 出版年：2006
• 出版时间：August, 2006
• 年：2006
• 卷：26
• 期：4
• 页码：335-345
• 全文大小：215 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Mechanics
  Characterization and Evaluation Materials
  Mechanical Engineering
  Inorganic Chemistry
  Nuclear Physics, Heavy Ions and Hadrons
  
• 出版者：Springer Netherlands
• ISSN：1572-8986

文摘

The generation, jet length and flow-regime change characteristics of argon plasma issuing into ambient air have been experimentally examined. Different torch structures have been used in the tests. Laminar plasma jets can be generated within a rather wide range of working-gas flow rates, and an unsteady transitional flow state exists between the laminar and turbulent flow regimes. The high-temperature region length of the laminar plasma jet can be over an order longer than that of the turbulent plasma jet and increases with increasing argon flow rate or arc current, while the jet length of the turbulent plasma is less influenced by the generating parameters. The flow field of the plasma jet has very high radial gradients of plasma parameters, and a Reynolds number alone calculated in the ordinary manner may not adequately serve as a criterion for transition. The laminar plasma jet can have a higher velocity than that of an unsteady or turbulent jet. The long laminar plasma jet has good stiffness to withstand the impact of laterally injected cold gas and particulate matter. It could be used as a rather ideal object for fundamental studies and be applied to novel materials processing due to its attractive stable and adjustable properties.