CAJ | 학술논문

为了分析大气压空气环境中氩气等离子体射流的特性，建立了二维轴对称的等离子体射流喷射模型；考虑待处理材料对等离子体射流的影响，利用Jets＆Poudres软件耦合求解了等离子体射流的可压缩N—s方程、能量方程以及K-e湍流方程；采用自由边界条件来处理射流等离子体的外边界条件，分析了射流等离子体的温度、速度以及所含空气组分等特性，并研究了工作气体体积流量以及喷口直径对喷射特性的影响。结果表明，射流等离子体的温度和轴向速度分布呈倒锥形分布，温度与轴向速度沿径向呈高斯分布衰减；等离子体径向速度的最大值出现在射流的尾部，且径向速度的峰值约为轴向速度峰值的1％；随着氩气体积流量的增加，等离子体的轴向体积流量显著增加，而等离子体温度逐渐降低，说明体积流量的增加提高了等离子体的冷却效应；随着喷口直径的增加，等离子体温度逐渐升高，而轴向速度的峰值显著减小，其最小值则几乎不变；在靠近喷嘴的等离子体射流高温高速区域，空气难以进入，该区域内的空气体积分数为3％～5％。
위료분석대기압공기배경중아기등리자체사류적특성，건립료이유축대칭적등리자체사류분사모형；고필대처리재료대등리자체사류적영향，이용Jets＆Poudres연건우합구해료등리자체사류적가압축N—s방정、능량방정이급K-e단류방정；채용자유변계조건래처리사류등리자체적외변계조건，분석료사류등리자체적온도、속도이급소함공기조분등특성，병연구료공작기체체적류량이급분구직경대분사특성적영향。결과표명，사류등리자체적온도화축향속도분포정도추형분포，온도여축향속도연경향정고사분포쇠감；등리자체경향속도적최대치출현재사류적미부，차경향속도적봉치약위축향속도봉치적1％；수착아기체적류량적증가，등리자체적축향체적류량현저증가，이등리자체온도축점강저，설명체적류량적증가제고료등리자체적냉각효응；수착분구직경적증가，등리자체온도축점승고，이축향속도적봉치현저감소，기최소치칙궤호불변；재고근분취적등리자체사류고온고속구역，공기난이진입，해구역내적공기체적분수위3％～5％。
In order to analyze the characteristics of Argon plasma jet under atmospheric air environment, a two-dimensional axis-symmetrical spurt model of plasma jet was established, in which the influences of a material work piece on plasma jet was considered, the Jets＆Poudres software was employed to solve the compressible N-S equations, energy equation and K-e turbulence equation, and the free boundary was used to deal with the outside boundary condition of plasma jet. Moreover, the plasma temperature, velocity and air percentage composition in plasma were analyzed, and the effects of Argon flow rates and nozzle diameters on spurt properties were also researched. The results show that, the distributions of plasma temperature and axial velocity present as inverted cone shape, and the distributions of attenuations of temperature and axial velocity are behaved as Gaussian function; The maximum value of radial velocity is 1% that of axis velocity, which appears at the tail of plasma jet; As Argon flow rates increase, the axial velocities of plasma jet increase apparently, and the plasma temperatures decrease gradually, indicating that the cool effect of plasma jet is enlarged at high gas flow rate; As nozzle diameters increase, the plasma temperatures increase gradually, and the peak values of axial velocities decrease sharply although the minimum values of axial velocities keep constant. Furthermore, in the region of high plasma temperature and velocity, it is difficult for air to enter, and the air percentages in this region are almost around 3%～5%.