Study on the wall ablation of heated compound-materials into discharge plasmas based on a modified model

Velocity of ablation vapor near the surface of heated compound-materials strongly affects the kinetic layer parameters modeled and manifested in the Knudsen layer. This paper discussed overlooked physics and clarified inaccuracies in the expression of velocity at the outer boundary of the kinetic layer induced by discharge plasma. The changes of average molecular mass coupling with discharge current on mass and momentum conservation equations in plasma layer were considered when modifying the expression of this boundary velocity. Our assessment of these effects indicated that velocity of ablation vapor showed a downtrend as the ratio of average molecular mass at inner and outer boundaries of plasma layer increased, which plays a decisive role in reducing the ablation rate. Compared with single species fluid model, the modified model that applies to the pyrolysis of heated compound-materials showed 56% drop in Teflon's ablation rate when plasmas were fully ionized.