Comparison of Booster Stage Engine Cycle
- Paper number
IAC-11,C4,1,13,x10207
- Author
Mr. Hideo Sunakawa, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Mr. Kaname Kawatsu, Japan
- Coauthor
Mr. Akihide Kurosu, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Dr. Nobuhiro Yamanishi, Japan
- Coauthor
Mr. Keiichiro Noda, Japan
- Year
2011
- Abstract
Engine cycle of booster stage engine shapes the characteristics of launch vehicle, and there are mainly 4 choices for the booster stage engine cycle, namely, the gas generator cycle, the staged combustion cycle, the closed expander cycle and the open expander cycle. The closed expander cycle and the staged combustion cycle are closed engine cycle, and achieves higher ISP (specific impulse) compared to the open engine cycle. Conventionally, the closed expander cycle is not used for booster stage because the maximum thrust is essentially limited. The staged combusition cycle is the highest performance booster stage engine, which is used for SSME, RD-180 and LE-7A. However, there are many technical challenges, such as start/stop sequence, thermal stress, engine cost and so on. The gas generator cycle is the most commonly applied to the booster stage engine. It is an open engine cycle and has potential as large thrust booster engine. The open expander cycle is the Japan's original engine cycle, which is adopted in LE-5B, upper stage engine of H-IIA and H-IIB. In this cycle, hydrogen pumped by the fuel turbopump is partly directed to the main combustion chamber cooling channels and then used to drive the turbines. The turbine drive hydrogen is injected into the main combustion flow at nozzle extension. This cycle has following advantages compared to other engine cycles: A)Simple engine configuration B)Reduced maximum system pressure and temperature C)Reduced heat impact to the turbines of turbopump D)Robustness to failure events JAXA has begun to study the post ‘H-IIA/B’ launch vehicle, called H-IIA/B evolution, which aims to significantly reduce cost and increase reliability comparable to the man-rated mission, and it will carve out the future space transportation. JAXA has selected an open expander cycle for the booster stage engine, called LE-X. LE-X engine will be the first booster engine in the world adopting an open expander cycle. We carried out a conceptual study of the booster stage engine cycle using a system analysis. The engine performance of the operational point is calculated considering engine power balance, and the cooling and heat transfer performance is evaluated with a steady-state heat transfer analysis tool REGEN (REGENerative cooling analysis code) which has been developed in JAXA. Using the system analysis, the trade study of the booster stage engine cycle is conducted and we will show the results in the final manuscript.
- Abstract document
- Manuscript document
(absent)