Showing papers on "Arcjet rocket published in 1972"

Performance testing of a solid propellant pulsed plasma microthruster.

Abstract: Extensive performance testing has been carried out on a solid propellant, pulsed plasma microthruster essentially identical to the four units aboard the DOD, Lincoln Experimental Satellite (LES)-6. Tests include measurements of thrust, specific impulse, thrust vector, impulse bit repeatability, intermittency and endurance. The results show good impulse bit repeatability and a well defined thrust vector. The impulse bit, with a 1.85-joule input, was found to be approximately 26 micronewton-seconds at 190 seconds specific impulse. Based upon the results of the intermittency tests, a better understanding of the intermittency mechanism has been achieved.

Propellant sidefeed-short pulse discharge thruster studies

Abstract: The technique of feeding a solid propellant into the discharge from the sides of the discharge was evaluated. The thrust/power ratio could be significantly effected by the included angle of V-shaped propellants and by the electrode length. This result implies that when results are compared at the same specific impulse it is possible to obtain higher thrust efficiencies. In particular, it was found that for a given discharge energy the thrust/power ratio correlated with propellant mass. Increasing the integral simultaneously increases both the gas dynamic and electromagnetic thrust. An analytic expression was formulated for ablated mass which comprehensively describes experimental data in terms of geometry and electrical parameters. The correlation of the product impulse x specific impulse with discharge energy was also described. It is suggested that the reliability of dry energy storage capacitors does not equal the reliability of liquid impregnated units when the comparison is made at the same joules/Kg rating.

Solid propellant powered rocket motor control system

Abstract: The invention is a control system for a solid propellant powered rocket motor, said system utilizing an electrical impulse generating sensor means responsive to heat generated by the burning propellant.

A study of graphite ablation in combined convective and radiative heating.

Abstract: Comparison of graphite ablation experiment results in the diffusion-controlled oxidation and sublimation regimes with results of an equilibrium chemistry, film coefficient ablation analysis. Mass transfer and energy transfer effects are considered. Tests were conducted in an arcjet facility at convective heating rates of 600 to 800 W/sq cm, radiative heating rates up to 2900 W/sq cm, with test specimen surface pressures of 0.06, 0.1, and 0.3 atm in an air stream. The experimental and analytical mass loss and surface temperature results agreed well when the carbon vapor thermodynamic properties from the JANAF tables are used in the analysis.

Bleed Cycle Propellant Pumping in a Gas-Core Nuclear Rocket Engine System

Abstract: The performance of ideal and real staged primary propellant pumps and bleed-powered turbines was calculated for gas-core nuclear rocket engines over a range of operating pressures from 500 to 5000 atm This study showed that for a required engine operating pressure of 1000 atm the pump work was about 08 hp/(lb/sec), the specific impulse penalty resulting from the turbine propellant bleed flow as about 10 percent; and the heat required to preheat the propellant was about 78 MW/(lb/sec) For a specific impulse above 2400 sec, there is an excess of energy available in the moderator due to the gamma and neutron heating that occurs there Possible alternative pumping cycles are the Rankine or Brayton cycles