Practical Uses of Liquid Methane in Rocket Engine Applications
- Paper number
IAC-06-C4.1.01
- Author
Mr. Todd Neill, Aerojet, United States
- Coauthor
Mr. Eric M. Veith, Aerojet, United States
- Coauthor
Mr. Donald Rousar, Aerojet, United States
- Coauthor
Mr. Donald Judd, Aerojet, United States
- Year
2006
- Abstract
Liquid methane has been considered an attractive rocket propellant for several decades. However, most United States rocket engine development efforts in the last 30 years have focused on using more traditional fuels such as hydrogen, kerosene, and earth storables, without any serious development or application of methane to propulsion systems.
Understanding key technical issues, including rocket ignition, combustion performance and stability, regenerative cooling and film cooling capabilities, system operation, and carbon deposition potential are necessary in order for liquid oxygen (LOX) and liquid methane (LCH4) rocket propellants to be considered practical.
Aerojet has recently completed liquid methane engine testing and cooling characterization studies. Results from these studies combined with methane studies conducted at Aerojet in the 1980’s address many of the aforementioned technical issues and will be discussed in this paper.
A summary of LOX / LCH4 torch igniter testing as well as 1,000 lbf thrust LOX / LCH4 engine test results will be discussed. Multiple test series were conducted using both radiation cooled and ablative chamber hardware. This engine testing yielded measured minimum C* efficiencies of 97% using non-optimized engine hardware, with expectations that better than 99% efficiency can readily be achieved with minor hardware optimization. The combustion process was shown to be stable in all tests, and the operating transition from poor quality methane (two-phase fluid) at startup to liquid-liquid, sub-cooled, steady state operation was demonstrated. Test results further demonstrated compatibility with high propellant mixture ratios and showed excellent boundary layer performance of methane as a chamber film coolant.
Results from an Aerojet funded investigation into the fundamental cooling characteristics of methane will also be addressed. In this effort, existing data from both Russian and U.S. sources is being compiled and will be coupled with heat transfer test data obtained from heated tube and engine tests to fill in existing knowledge gaps.
- Abstract document
- Manuscript document
IAC-06-C4.1.01.pdf (🔒 authorized access only).
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