NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Combustion Stability Analyses for J-2X Gas Generator DevelopmentThe National Aeronautics and Space Administration (NASA) is developing a liquid oxygen/liquid hydrogen rocket engine for upper stage and trans-lunar applications of the Ares vehicles for the Constellation program. This engine, designated the J-2X, is a higher pressure, higher thrust variant of the Apollo-era J-2 engine. Development was contracted to Pratt & Whitney Rocketdyne in 2006. Over the past several years, development of the gas generator for the J-2X engine has progressed through a variety of workhorse injector, chamber, and feed system configurations. Several of these configurations have resulted in injection-coupled combustion instability of the gas generator assembly at the first longitudinal mode of the combustion chamber. In this paper, the longitudinal mode combustion instabilities observed on the workhorse test stand are discussed in detail. Aspects of this combustion instability have been modeled at the NASA Marshall Space Flight Center with several codes, including the Rocket Combustor Interaction Design and Analysis (ROCCID) code and a new lumped-parameter MatLab model. To accurately predict the instability characteristics of all the chamber and injector geometries and test conditions, several features of the submodels in the ROCCID suite of calculations required modification. Finite-element analyses were conducted of several complicated combustion chamber geometries to determine how to model and anchor the chamber response in ROCCID. A large suite of sensitivity calculations were conducted to determine how to model and anchor the injector response in ROCCID. These modifications and their ramification for future stability analyses of this type are discussed in detail. The lumped-parameter MatLab model of the gas generator assembly was created as an alternative calculation to the ROCCID methodology. This paper also describes this model and the stability calculations.
Document ID
20100022010
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Hulka, J. R.
(Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Protz, C. S.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Casiano, M. J.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Kenny, R. J.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
May 3, 2010
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
M10-0078
Meeting Information
Meeting: 57th JANNAF Propulsion Meeting (JPM)
Location: Colorado Springs, CO
Country: United States
Start Date: May 3, 2010
End Date: May 7, 2010
Sponsors: NASA Headquarters, Department of the Navy, Department of the Air Force, Department of the Army
Funding Number(s)
CONTRACT_GRANT: NNM05AB50C
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available