Numerical investigation of transport phenomena of arc plasma in argon-oxygen gas mixture
Numerical investigation of transport phenomena of arc plasma in argon-oxygen gas mixture
复制标题
氩氧气体中电弧等离子体输运现象的数值研究
DOI：
10.1016/j.ijheatmasstransfer.2020.119708
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发表时间：
2020-06
影响因子：
5.2
通讯作者：
Fan Ding
中科院分区：
文献类型：
--
作者：
Wang Xinxin;Luo Yi;Chi Luxin;Fan Ding
气体混合物广泛应用于各种弧焊工艺中，以改善电弧性能，从而提高焊接质量。本文研究了氩-氧混合气体中电弧等离子体的特性，建立了二维轴对称模型来研究电弧中的输运现象，并采用联合扩散系数法处理扩散。将混合气体分别应用于传统的钨惰性气体（TIG）电弧炬和双气体保护电弧炬。TIG电弧考虑输入混合气体中5%和20%的氧气质量分数，而双气保护电弧则考虑外保护气体中20%的氧气质量分数。重点讨论了两种电弧中电弧电流对分离的影响。研究了氧加入氩对TIG电弧温度的影响。结果表明：TIG电弧的氧集中在靠近弧轴和电极的区域，电流的增加使阴极尖端附近的氧浓度降低，但有利于弧轴附近的氧向阳极的传质；而对于双气体保护电弧，氧气在电弧的外围区域明显集中，并向电弧轴方向扩散，在阳极附近的氧气质量分数要低得多。在氩气中加入氧气会使TIG电弧中靠近阳极的弧柱收缩。两种电弧在阳极上方0.1 mm处的氧质量分数分布不均匀，表明氧与熔融阳极表面反应的分布不均匀。
Mixtures of gases are utilized widely in a variety of arc welding processes to improve the arc property and thus the welding quality. This research focuses on the properties of the arc plasma in argon-oxygen gas mixture and a two dimensional (2D) axial symmetrical model is developed to investigate the transport phenomena in such arc, with diffusion treated by using combined diffusion coefficient approach. The gas mixture is applied to conventional tungsten inert gas (TIG) arc torch and a double-gas-shielding arc torch, respectively. Two different mass fractions of oxygen, i.e. 5% and 20%, in input gas mixture, are considered for the TIG arc, whereas that of 20% is taken into account for the outer shielding gas in the double-gas-shielding arc. The influence of the arc current on the demixing in the two types of arc is highlighted. The effect of the oxygen addition to argon on the TIG arc temperature is exhibited. It is found that for the TIG arcs, the oxygen concentrates in the regions close to the arc axis and to the electrodes, and increased current reduces the oxygen concentration near the cathode tip, but facilitates the mass transfer of the oxygen near the arc axis towards the anode; while for the double-gas-shielding arcs, the oxygen concentrates markedly in the periphery region of the arc and diffuses slightly towards the arc axis, with much lower mass fraction of the oxygen near the anode, for all the cases considered. Adding oxygen to the argon constricts the arc columns near the anode as compared with those in the pure argon for TIG arc. The oxygen mass fraction distribution 0.1 mm above the anode is uneven for the both types of the arc, implying nonuniform distribution of the oxygen reacting with the surface of the molten anode.
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影响因子：
6.3
作者：
A. Traidia;F. Roger
通讯作者：
A. Traidia;F. Roger
影响因子：
8.6
作者：
Murphy
通讯作者：
Murphy
影响因子：
3.4
作者：
Murphy, AB
通讯作者：
Murphy, AB
DOI：
10.1016/j.msea.2004.05.057
发表时间：
2004-08-25
影响因子：
6.4
作者：
Lu, SP;Fujii, H;Nogi, K
通讯作者：
Nogi, K
影响因子：
3.3
作者：
Shanping Lu;H. Fujii;K. Nogi
通讯作者：
Shanping Lu;H. Fujii;K. Nogi