DYNAMIC PERFORMANCE OF LOW THRUST COLD GAS REACTION JETS IN A VACUUM
Rept. for Mar 1965-Apr 1966
AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS
Pagination or Media Count:
The pulsed propulsive performance of low-thrust reaction jets, typical of those used for small spacecraft attitude control, is analyzed and compared with the results of laboratory experiments. Five gases, hydrogen, nitrogen, ammonia, Freon-12, and Freon-14, are investigated using a 48 to 1 expansion ratio nozzle. The transient processes which dominate the short-pulse or limit-cycle mode of thruster operation are formulated. These relationships show good correlation with the data. The apparatus, procedures, and techniques required to obtain accurate test results for a low-thrust, dynamic mode of operation are described. Impulse bit size, gas consumption, and specific impulse are characterized in terms of thruster geometry, gas properties, and command pulse width to provide a basis for optimum system design. A simplified method for calculating dynamic impulse bit size, dynamic gas consumption, and pulsed specific impulse as a function of command pulse width is developed. Finally, the effective performance of the gases tested is evaluated by a technique which includes the influence of tank and propellant weights, as well as specific impulse.
- Unmanned Spacecraft