Parametric study of high energy plasmas for electrothermal-chemical propulsion applications

Abstract

Theoretical calculations are performed with a one-dimensional (1-D), steady state, isothermal computer plasma model to define plasma output parameters for various input electrical energies and capillary radii of relevance to the electrothermal-chemical (ETC) propulsion concept. Three capillaries of 1.92, 4.75, and 7.0 mm radius, and a fixed length of 11.84 cm, were chosen for this study with input currents between 30 and 350 kA. Plasmas are categorized according to their total power and energy levels (based on a 3-ms pulse width) and are compared with respect to their resistance, exit pressure, and core plasma temperature. The input power ranges from 0.17 to 1.89 GW, for input energies from 0.49 to 5.80 MJ, which is considered suitable coverage for ETC ignition through ETC enhanced propulsion concepts. The study shows that the range of resistance, pressure, and temperature are 12.8-195 m, 19.8-2000 MPa, and 2.9-13.5 eV, respectively, for the chosen capillary geometry. Flow conditions for plasma calculations include choked (no pressure boundary) and unchoked (450-MPa pressure boundary) for some calculations. Results from the computational model and interpretations from the perspective of capillary implementation into ETC propulsion concepts are also included.

The temperature measurement of the electrothermal-chemical launcher plasma by atomic emission spectroscopy

“…It is known that the plasma temperatures of the electrothermal and electromagnetic accelerator are between 0.35 (4000 K) and 3 eV (33 700 K) [4]- [7]. Besides its high temperature, there are large quantities of carbon particles in the plasma, thus, the common optical methods and instruments, such as coherent anti-strokes raman spectroscopy (CARS) [8], cannot be used for temperature diagnostics of the plasmas of ETC launchers.…”