Experimental and Theoretical Studies of a Nitrogen Arc With Copper Evaporation From the Anode: RIA

氮气电弧阳极蒸发铜的实验和理论研究：RIA

• 批准号: 8910685
• 负责人: Kasra Etemadi
• 金额: $ 7万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1991-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8910685&HistoricalAwards=false
• 关键词: Experimental; Theoretical; Studies; Nitrogen; Arc

This proposal is concerned with experimental and theoretical studies of thermal plasmas, in particular with the impact of anode evaporation to the anode region of a high intensity nitrogen arc. An improved emission spectroscopic technique will be utilized to measure the temperature and the vapor density distribution of the anode material (copper). In a two-step process the unresolved (0,0) emission band of molecules at 3914.4 A and the spectral line of CuI at 5218.2 A are chosen for the measurements. The plasma properties will be also determined by the relative line intensity method of CuI using 5105.5, 5153.2, 5218.2, 5700.2, and 5782.1 A spectral lines. Holographic interferometry will be used for flow visualization and for temperature measurements in the lower temperature regions (in the absence of turbulence and in the presence of an axisymmetrical plasma). An already existing computer program for the modeling of a mixture of argon and copper thermal plasma will be modified for a nitrogen-copper free burning arc. The thermodynamic and transport properties of the nitrogen-copper plasma required for the modeling will be calculated by a program written for a general multicomponent two-temperature plasma. In the intended study the plasma is assumed to be optically thin and in the state of Local Thermodynamic Equilibrium. Thermal plasmas can be applied for melting, cutting, welding and refining materials, and they play an important role in high power interrupters, arc lamps, reduction metallurgy and plasma spraying. A change in the anode geometry due to evaporation can have a deleterious affect on the desired heat and mass transfer and can damage switching devices. By applying advanced optical methods to determine the temperature and flow characteristics of the plasma in the vicinity of the electrodes, the evaporation process can be better understood.

该提案涉及热等离子体的实验和理论研究，特别是阳极蒸发对高强度氮电弧阳极区域的影响。 将利用改进的发射光谱技术来测量阳极材料（铜）的温度和蒸气密度分布。 在两步过程中，选择 3914.4 A 处的分子未解析 (0,0) 发射带和 5218.2 A 处的 CuI 谱线进行测量。 等离子体特性也将通过使用 5105.5、5153.2、5218.2、5700.2 和 5782.1 A 谱线的 CuI 相对线强度方法来确定。 全息干涉测量将用于流动可视化和较低温度区域的温度测量（在没有湍流且存在轴对称等离子体的情况下）。 现有的用于模拟氩和铜热等离子体混合物的计算机程序将被修改为无氮铜燃烧电弧。 建模所需的氮-铜等离子体的热力学和传输特性将通过为一般多组分两温度等离子体编写的程序来计算。 在预期的研究中，假设等离子体是光学薄的并且处于局部热力学平衡状态。 热等离子体可用于材料的熔化、切割、焊接和精炼，在大功率灭弧室、弧光灯、还原冶金和等离子喷涂等领域发挥着重要作用。 由于蒸发而导致的阳极几何形状的变化会对所需的热量和质量传递产生有害影响，并可能损坏开关装置。 通过应用先进的光学方法来确定电极附近等离子体的温度和流动特性，可以更好地了解蒸发过程。