Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micron-sized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles. 1. Introduction Aluminum powder is a common ingredient in conventional solid rocket propellants. It is used to increase specific impulse, , as well as stability. The properties and recent availability of nanoscale aluminum (nAl) have motivated recent efforts in new solid propellant formulations. For example, Kuo et al. [1] discussed the potential use of nanosized powders for rocket propulsion in a recent paper. Many of the potential advantages listed for these particles are short ignition delay, fast burning times, and the possibility to act as an energetic gelling agent. Using nAl has been shown to produce a significant increase in performance with conventional solid propellants [2, 3]. Researchers showed that replacing 50？μm particles with the same amount of nominally 100？nm particles in AP-based propellants could result in a burning rate increase of up to 100% [4]. Most of these characteristics can be attributed to the high-specific surface area of the nanoscale particles [1, 5]. The possible drawbacks of nAl are the reduction in active aluminum content, electrostatic discharge (ESD) sensitivity when dry, and poor rheological properties. Other research has been conducted pairing this increased reactivity of nAl with less
References
[1]
K. K. Kuo, G. A. Risha, B. J. Evans, and E. Boyer, “Potential usage of energetic nano-sized powders for combustion and rocket propulsion,” Materials Research Society Symposium Proceedings, vol. 800, pp. 3–14, 2003.
[2]
A. Dokhan, E. W. Price, J. M. Seitzman, and R. K. Sigman, “The effects of bimodal aluminum with ultrafine aluminum on the burnign rates of solid propellants,” Proceedings of the Combustion Institute, vol. 29, no. 2, pp. 2939–2946, 2002.
[3]
A. Shalom, H. Aped, M. Kivity, and D. Horowitz, “The effect of nanosized aluminum on composite propellant properties,” in Proceedings of the 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, July 2005.
[4]
L. Galfetti, F. Severini, L. T. De Luca, and L. Meda, “Nano-propellants for space propulsion,” in Proceedings of the 4th International Spacecraft Propulsion Conference, vol. 4, Sardinia, Italy, June 2004.
[5]
M. A. Trunov, M. Schoenitz, and E. L. Dreizin, “Ignition of aluminum powders under different experimental conditions,” Propellants, Explosives, Pyrotechnics, vol. 30, no. 1, pp. 36–43, 2005.
[6]
G. A. Risha, Y. Huang, R. A. Yetter, V. Yang, S. F. Son, and B. C. Tappan, “Combustion of aluminum particles with steam and liquid water,” in Proceedings of the 44th AIAA Aerospace Sciences Meeting and Exhibit, January 2006.
[7]
V. G. Ivanov, M. N. Safronov, and O. V. Gavrilyuk, “Macrokinetics of oxidation of ultradisperse aluminum by water in the liquid phase,” Combustion, Explosion and Shock Waves, vol. 37, no. 2, pp. 173–177, 2001.
[8]
A. Ingenito and C. Bruno, “Using aluminum for space propulsion,” Journal of Propulsion and Power, vol. 20, no. 6, pp. 1056–1063, 2004.
[9]
E. Shafirovich, P. E. Bocanegra, C. Chauveau, and I. G？kalp, “Nanoaluminium—water slurry: a novel “green” propellant for space applications,” in Proceedings of the 2nd International Conference on Green Propellants for Space Propulsion, vol. 2, Sardinia, Italy, June 2004.
[10]
O. Rasor and O. R. Portland, U.S. Patent Application for a “Power Plant”, 1939.
[11]
O. J. Elgert and A. W. Brown, In Pile Molten Metal-Water Reaction Experiment, U.S. Atomic Energy, 1956.
[12]
L. Leibowitz and L. W. Mishler, “A study of aluminum-water reactions by laser heating,” Journal of Nuclear Materials, vol. 23, no. 2, pp. 173–182, 1967.
[13]
T. F. Miller and J. D. Herr, “Green rocket propulsion by reaction of Al and Mg powders and water,” in Proceedings of the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, July 2004.
[14]
J. P. Foote, J. T. Lineberry, B. R. Thompson, and B. C. Winkelman, “Investigation of aluminum particle combustion for underwater propulsion applications,” in Proceedings of the 32nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 1996.
[15]
R. W. Humble, G. N. Henry, and W. J. Larson, Space Propulsion Analysis and Design, chapter 6, McGraw-Hill, New York, NY, USA, 1st edition, 1995.
[16]
V. G. Ivanov, O. V. Gavrilyuk, O. V. Glazkov, and M. N. Safronov, “Specific features of the reaction between ultrafine aluminum and water in a combustion regime,” Combustion, Explosion and Shock Waves, vol. 36, no. 2, pp. 213–219, 2000.
[17]
G. A. Risha, S. F. Son, R. A. Yetter, V. Yang, and B. C. Tappan, “Combustion of nano-aluminum and liquid water,” Proceedings of the Combustion Institute, vol. 31, no. 2, pp. 2029–2036, 2007.
[18]
T. R. Sippel, S. F. Son, G. A. Risha, and R. A. Yetter, “Combustion and characterization of nanoscale aluminum and ice propellants,” in Proceedings of the 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, July 2008.
[19]
A. Dokhan, The effects of aluminized particle size on aluminized propellant combustion [Ph.D. thesis], Aeronautics and Astronautics Department , Georgia Institute of Technology, Atlanta, Ga, USA, 2002.
[20]
Y. S. Kwon, A. A. Gromov, and J. I. Strokova, “Passivation of the surface of aluminum nanopowders by protective coatings of the different chemical origin,” Applied Surface Science, vol. 253, no. 12, pp. 5558–5564, 2007.
[21]
M. Cliff, F. Tepper, and V. Lisetsky, “Ageing characteristics of Alex nanosize aluminum,” in Proceedings of the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2001.
[22]
C. Franson, O. Orlandi, C. Perut et al., “Al/H20 and Al/H20/H202 frozen mixtures as examples of new composite propellants for space application,” in Proceedings of the 7th International Symposium on Launcher Technologies, Barcelona, Spain, 2007.
J. T. Mang, R. P. Hjelm, S. F. Son, P. D. Peterson, and B. S. Jorgensen, “Characterization of components of nano-energetics by small-angle scattering techniques,” Journal of Materials Research, vol. 22, no. 7, pp. 1907–1920, 2007.
[25]
T. R. Sippel, Characterization of nanoscale aluminum and ice solid propellants [M.S. thesis], Mechanical Engineering Department, Purdue University, West Lafayette, Ind, USA, 2009.
[26]
R. A. Yetter, G. A. Risha, T. Connell et al., “Novel energetic materials for space propulsion,” in Presentation, AFOSR/NASA Office of Chief Engineer Joint Contractors / strategic Planning Meeting in Chemical Propulsion, Vienna, Va, USA, 2008.
[27]
ThrustCurve, John Coker, 2012, http://www.thrustcurve.org/.
[28]
“RockSim, Ver. 8.0,” Apogee Components, Inc., Colorado Springs, Colo, USA, 2009.
