An experimental investigation on LOX/LCH4 reaction control thrusters
This work describes the development and preliminary testing of a thrust measurement system, in combination with a propellant feed and automation controls systems to test the performance of 8.9 to 35.6 N (2 to 8 lbf) LOX/Methane reaction control thrusters. LOX/LCH4 has come to be the main focus of next generation "green" propellants for future space exploration. As there is limited experience with this propellant combination, an effort is being conducted to research performance of rockets using these propellants. The development of a thrust measurement, propellant feed, and automation controls systems is necessary for proper testing and qualification of thruster performance. The propellant feed system includes three subsystems: (i) Liquid methane production and delivery subsystem, (ii) LOX delivery subsystem, and (iii) Propellants automated flow control and monitoring subsystem. A cart-based mobile liquid methane delivery system was designed in order to provide fuel to meet combustion requirements; a 2.2 L liquid methane production unit was also integrated within this system. Liquid methane production is accomplished with a condenser and utilizing liquid nitrogen as a chiller. Flow control and monitoring of the system is done remotely from a control room and is achieved by component commands sent through a LabVIEW program interface and a DAQ system. The program allows the automated execution of thruster experimental procedures and precision in control of timing and measurement. A torsional based thrust measurement system uses thrust to generate a moment upon a central axis, which induces displacement captured by a laser positioning sensor. Torsional pivots are used to provide a consistent and measurable resistance to thrust; displacement is correlated to a thrust value via the use of a calibration curve. Preliminary integration testing was conducted to ensure proper system functionality and response by firing a LOX/LCH4 thruster at ambient conditions.^
Acosta-Zamora, Arturo, "An experimental investigation on LOX/LCH4 reaction control thrusters" (2012). ETD Collection for University of Texas, El Paso. AAI1533202.