Effect of a non-ideal state equation on the steady state critical flow characteristics in ablative capillaries

The non-ideal continuity, momentum and energy equations describing plasma characteristics in confined high-pressure discharges in cylindrical ablative capillaries were solved numerically. The model equations used included (a) viscous and radiative and thermal conduction effects, (b) space dependent ionization and correction to Spitzer's electrical conductivity and (c) non-ideal equation of state, as provided by SESAME library. For illustration, the case of polyethylene capillaries and discharge parameters appropriate for electrothermal launchers were considered. Analysis of the results indicated the consideration of the non-ideal equation of state to have significant consequences on the plasma characteristics. The sensitivity of these effects to variations in the discharge parameters was then studied and the results are also presented here. In the last part of the work we present the results of the implementation of a method aimed to determine self-consistent boundary conditions at the ends of the capillary as well as of the investigation of their effect on the solutions obtained.