Effect of Changing Source Capillary Radius on Bulk Flow Parameter Scaling Laws for Hypersonically Expanding Arc-Ablated Polycarbonate Plasma for Fusion and Space Applications

摘要

Capillary pulsed electrothermal plasma source coupled to a linear converging-diverging nozzle was previously found to be adequate as a simulator for the supersonic bulk flow patterns of the aerosol particulates generated following a hard disruption event that damages the plasma facing components in a fusion reactor. A similar system can assume an important role in the computational studies related to space electric propulsion and electrostatic ion thrusters. Scaling laws for the prediction of bulk temperature, density, pressure, plasma bulk velocity and Mach number as a function of the axial length traversed measured from the source exit had been proposed previously for an arc-ablated polycarbonate plasma jet evolving into a vacuum chamber via the transition nozzle. In the present work, the source capillary radius has been varied and with the sectional lengths remaining fixed, the converging and diverging angles have also been varied with it, as the diverging exit Mach number was kept constant at a high-hypersonic value similar to 18. The effect of changing source capillary radius as well as the transition region geometry on the aforesaid bulk flow parameters has been studied computationally and new scaling laws have been proposed.