Asymmetrical Gas Flow in a Tube and Pressure in a Pressure Chamber Caused by Ablation Arcs

Abstract

A series of studies about an ablation arc burning in an ablative capillary tube which has a pressure chamber at one end of it, has been reported recently. The processes of the gas flow have been described by a model, and the process that the flow stagnation point moves from the center of the tube to the tube end of the pressure chamber side and the gas flow becomes asymmetrical, is called second process. In this paper, the ther-modynamical properties of the gas flow in the tube corresponding to the second process are investigated theoretically and experimentally. The formulas describing the thermodynamical properties in the tube and in the pressure chamber are derived. The relation between the movement of stagnation point and the pressure in the pressure chamber is presented also. The experimental information including the arc voltage, current, ablated mass and the tube structure are used to obtain the simplifying formulas. A comparison between the measured pressure and the calculated pressure by the simplifying formulas in the pressure chamber indicates that the theoretical model can adequately describe the pressure raising in the pressure chamber. Illustrative analytical and numerical solutions of the equations are also presented. The experimental results support the theoretical model.