用于大气环境中的氮等离子体枪束流模拟

Beam Current Simulation of Plume from Nitrogen Plasma Gun in Atmosphere

为了对等离子体应用设计提供依据，在局部热力学平衡条件下，应用差分网格法，通过解RNG k-ε方程模拟了用于大气环境中的氮等离子体枪的束流，得到了与实验测得的基本一致的等离子体束型．计算了不同气体流量条件下等离子体束流的温度场，并通过描绘等离子体束流中温度为600K的边界得到了等离子体束型．结果表明：当流量F〈0.8m^3／h时，随着流量的减少，束型变小；当F〉0、8m^3／h时，等离子体束型分布趋于稳定，此时能够为等离子体的应用提供较好的离子源．等离子束径在7～8mm处达到最大，此处应为等离子体应用的最佳范围．

To provide a theoretic foundation for industrial plasma applications, in locally thermodynamic equilibrium, the beam current from a nitrogen plasma gun was simulated in atmosphere, through .solving the RNG k-ε equation, and difference grid. The shape of beam current was thus got and it was basically in conformity to that measured in simulation. The temperature field of the plasma beam current was calculated on the condition of different gas flux, with the shape of beam current found through plotting its boundary at 600 K. The results showed that when the gas flux F〈 0.8 m^3/h, the size of beam current decreases with decreasing gas flux, and when F 〉0.8 m^3/h, the size distribution of beam current tends to be stable. If so, a better plasma source is available to plasma applications. It was verified the best size range of beam current for plasma applications is 7-8 mm which is also the maximum one.