Characterizing High-Energy-Density Propellants for Space Propulsion Applications

Paper number

IAC-06-C4.P.1.10

Author

Mr. Timothy Kokan, Georgia Institute of Technology, United States

Coauthor

Dr. John Olds, SpaceWorks Engineering, Inc. (SEI), United States

Year

2006

Abstract

There exists wide ranging research interest in high-energy-density matter (HEDM) propellants as a potential replacement for existing industry standard fuels (LH2, RP-1, MMH, UDMH) for liquid rocket engines.  The U.S. Air Force Research Laboratory, the U.S. Army Research Lab, the NASA Marshall Space Flight Center, and the NASA Glenn Research Center each either recently concluded or currently has ongoing programs in the synthesis and development of these potential new propellants.  

Most conceptual rocket engine powerhead design tools (e.g. NPSS, ROCETS, and REDTOP-2) require several thermophysical properties of a given propellant in order to perform conceptual vehicle designs.  These properties include enthalpy, entropy, density, viscosity, and thermal conductivity.  For most of these potential new HEDM propellants, this thermophysical data either does not exist or is incomplete over the range of temperature and pressure necessary for liquid rocket engine design and analysis.  

If one wishes to use HEDM propellants in a conceptual vehicle design, a technique for determining the thermophysical properties of these propellants must be used.  Current computational techniques cannot model complex HEDM molecules to the level of accuracy needed for rocket engine powerhead design tools.  As a result, a technique for determining the thermophysical properties of potential new rocket engine propellants has been developed and is presented.  This technique uses a combination of analytical/computational methods and experimental investigations.  Quantum mechanics and molecular dynamics are used to model these new HEDM propellants at a molecular level.  By modeling the motion and distribution of the simulated molecules, one can calculate all the thermophysical properties of interest.  Experimental investigations are performed to both verify and improve the predictive accuracy of the computational methods.  

Results are provided for two HEDM fuels: 2-azido-N, N-dimethylethanamine (DMAZ) and quadricyclane.  In each case, the calculated thermophysical properties are compared against experimental measurements and good agreement is achieved.  The results of a conceptual vehicle design case study utilizing the calculated thermophysical properties of DMAZ and quadricyclane are presented.  The case study chosen is the lunar lander ascent stage of NASA’s proposed lunar Exploration Systems Architecture Study (ESAS).  This case study helps to quantify the operational, cost, and performance benefits of using DMAZ or quadricyclane over existing industry standard hydrocarbon fuels for space propulsion applications.

Abstract document

IAC-06-C4.P.1.10.pdf

Manuscript document

IAC-06-C4.P.1.10.pdf (🔒 authorized access only).

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