Analytical study of nozzle performance for nuclear thermal rockets

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:6123570

Davidian, K O; Kacynski, K J

Nuclear propulsion has been identified as one of the key technologies needed for human exploration of the Moon and Mars. The Nuclear Thermal Rocket (NTR) uses a nuclear reactor to heat hydrogen to a high temperature followed by expansion through a conventional convergent-divergent nozzle. A parametric study of NTR nozzles was performed using the Rocket Engine Design Expert System (REDES) at the NASA Lewis Research Center. The REDES used the JANNAF standard rigorous methodology to determine nozzle performance over a range of chamber temperatures, chamber pressures, thrust levels, and different nozzle configurations. A design condition was set by fixing the propulsion system exit radius at five meters and throat radius was varied to achieve a target thrust level. An adiabatic wall was assumed for the nozzle, and its length was assumed to be 80 percent of a 15 degree cone. The results conclude that although the performance of the NTR, based on infinite reaction rates, looks promising at low chamber pressures, finite rate chemical reactions will cause the actual performance to be considerably lower. Parameters which have a major influence on the delivered specific impulse value include the chamber temperature and the chamber pressures in the high thrust domain. Other parameters, such as 2-D and boundary layer effects, kinetic rates, and number of nozzles, affect the deliverable performance of an NTR nozzle to a lesser degree. For a single nozzle, maximum performance of 930 seconds and 1030 seconds occur at chamber temperatures of 2700 and 3100 K, respectively.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 6123570
• Report Number(s): N-92-11126; NASA-TM-105251; E-6580; NAS-1.15:105251; AIAA-91-3578; CONF-9109226-
• Resource Relation: Conference: AIAA/NASA/OAI conference on advanced space exploration initiative (SEI) technologies, Cleveland, OH (United States), 3-4 Sep 1991; Other Information: Sponsored in part by NASA, AIAA, and OAI
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
NOZZLES
SPECIFICATIONS
ROCKET ENGINES
SPACE PROPULSION REACTORS
EXPERT SYSTEMS
EXPLORATION
MARS PLANET
MOON
PARAMETRIC ANALYSIS
PERFORMANCE
PROPULSION SYSTEMS
ENGINES
MOBILE REACTORS
PLANETS
POWER REACTORS
PROPULSION REACTORS
REACTORS
SATELLITES
SPACE POWER REACTORS
NESDPS Office of Nuclear Energy Space and Defense Power Systems
210600* - Power Reactors
Auxiliary
Mobile Package
& Transportable