大气压下空气电弧组分与折射率计算及其在莫尔偏折中的应用

发布时间：2018-10-23 21:24

【摘要】：大气等离子体作为一种常见的等离子体,以其低成本、易生成等优点在材料加工、冶金切割、熔断焊接以及医疗杀菌等方面有着广泛应用。本文基于Eindhoven模型,结合Giuliano提出的配分函数计算方法对大气等离子体的组分和折射率进行了计算,并基于莫尔偏折对大气电弧进行了温度诊断。配分函数是关系组分结果是否准确的重要参数。本文采用Giuliano分组法计算了大气等离子体的原子及离子配分函数,并且与传统的半经验延展法结果对比,论证了使用Giuliano分组法代替半经验延展法在本文论述条件下的可行性;分子方面,本文采用了Mayer提出的简化计算方法计算了大气等离子体分子及其离子的配分函数,并与莫尔斯势能法进行了比较,论证了使用Mayer简化法代替莫尔斯势能法在本文论述条件下的可行性。组分是对大气等离子体光学参数及温度分布进行研究的前提。本文基于Eindhoven模型对大气等离子体组分进行了计算,其中,Giuliano提出的分组法被应用于配分函数的计算中,极大程度地简化了 Eindhoven方程组的阶数,同时,使用了两种简化配分函数算法计算出了它们各自的组分值。在格拉斯通戴尔公式的基础上,依据统一的折射率计算模型,计算得到了折射率温度曲线。同时对比了考虑离子对折射率贡献与否对最终折射率结果造成的差异,并给出了忽略离子的温度适用范围。实验方面,搭建了莫尔偏折实验平台,用以测量大气电弧等离子体的折射率分布。通过将折射率分布与不同配分函数处理方法计算的折射率温度曲线进行反演,得到了大气电弧的温度分布。另一方面,搭建了光谱分析实验平台对大气电弧进行温度测量,从侧面印证了莫尔偏折实验结果的准确性。最终本文对不同配分函数处理方法得到的折射率温度曲线及温度分布进行了对比分析,得到了不同配分函数处理方法各自的适用范围。结果表明,三种配分函数处理方法在1标准大气压12000K以下都能够进行较为准确的温度诊断。在折射率方面,采用简化比值法的结果仅在温度低于8600K与17040K-21410K间和分组法的结果误差小于1%;忽略高能级法与Giuliano分组法除了在10910K-11410K和14680K-21420K产生的误差大于1%外,其余温度区间结果都与Giuliano分组法的折射率结果十分吻合。
[Abstract]:As a common plasma, atmospheric plasma has been widely used in material processing, metallurgical cutting, welding and medical sterilization for its advantages of low cost and easy generation. Based on the Eindhoven model and the partition function method proposed by Giuliano, the composition and refractive index of atmospheric plasma are calculated, and the temperature of atmospheric arc is diagnosed based on moire deflection. Partition function is an important parameter in relation to the accuracy of component results. In this paper, the atomic and ion partition functions of atmospheric plasma are calculated by Giuliano grouping method, and compared with the results of traditional semi-empirical extension method, the feasibility of using Giuliano grouping method instead of semi-empirical extension method in this paper is demonstrated. In molecular terms, the partition functions of atmospheric plasma molecules and their ions are calculated by using the simplified calculation method proposed by Mayer and compared with the Morse potential energy method. The feasibility of using Mayer simplified method to replace Morse potential energy method under the conditions discussed in this paper is demonstrated. Component is the premise of studying the optical parameters and temperature distribution of atmospheric plasma. In this paper, the components of atmospheric plasma are calculated based on Eindhoven model. Among them, the grouping method proposed by Giuliano is applied to the calculation of partition function, which greatly simplifies the order of Eindhoven equations. Two simplified partition function algorithms are used to calculate their respective component values. On the basis of Grantondale's formula, the temperature curve of refractive index is calculated according to the unified refractive index calculation model. At the same time, the difference between the final refractive index results by considering the contribution of ion to refractive index is compared, and the applicable range of temperature for neglecting ions is given. In the aspect of experiment, an experimental platform of moire deflection is built to measure the refractive index distribution of atmospheric arc plasma. The temperature distribution of atmospheric arc is obtained by inversion of refractive index distribution and refractive index temperature curve calculated by different partition function. On the other hand, the experimental platform of spectral analysis is built to measure the temperature of atmospheric arc, which verifies the accuracy of the experimental results of Mohr deflection. Finally, the temperature curve and temperature distribution of refractive index obtained by different partition function processing methods are compared and analyzed, and the applicable range of different partition function processing methods is obtained. The results show that the three partition function processing methods can be used to diagnose temperature accurately below 1 standard atmospheric pressure of 12000K. In terms of refractive index, the results of simplified ratio method are only less than 1 when the temperature is lower than 8600 K and 17040K-21410K and the error of grouping method is less than 1, ignoring that the error between high energy level method and Giuliano group method is more than 1% except in 10910K-11410K and 14680K-21420K. The results of other temperature ranges are in good agreement with the refractive index results of Giuliano grouping method.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O53

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