气流稳定作用数值研究

Numerical investigation for stabilizing effect of external gas flow

用数值方法研究了外部气流对电弧等离子体螺旋不稳定性的影响 ,给出了外部气流满足的方程及稳定作用项的解析表达式 .证明 :外加气流对短波情况影响大 ,有利于稳定电弧 ;但对中长波情况影响很小 .计算结果表明 ,随着外部气流剪切粘滞系数的增大 ,其对螺旋不稳定性的稳定作用也增大 ,有助于电弧稳定 .

The effect of external gas flow on helical instability of arcs is studied by using numerical method. The equation and the analytic expression that corresponds to the term of a gas flow stabilizing effect are deduced. The conclusions are drawn below: In the short wavelength case, the effect of external gas flow is great, so it is beneficial to stabilizing arcs. However, its effect is very small for the intermediate and long wavelength. At the same time, numerical results show that the stabilizing effect of the flow on helical instability increases with increasing the shear viscosity of external gas flow. Hence it will help to stabilize arcs.