Begell House Inc.
International Journal of Energetic Materials and Chemical Propulsion
IJEMCP
2150-766X
10
3
2011
RECENT ADVANCES IN ENERGETIC MATERIALS IN SWEDEN, ESPECIALLY AT THE FOI
187-215
10.1615/IntJEnergeticMaterialsChemProp.2012001387
Bo
Janzon
SECRAB Security Research, Vasteras, Sweden
Henric
Ostmark
FOI, Swedish Defence Research Agency, Division of Defence and Security, Systems and Technology, Tumba, Sweden
energetic materials
green energetics
high explosives
propellants
synthesis
high performance
low environmental impact
During the twentieth century, few breakthroughs occurred in energetic materials. Hexanitrobenzene was judged only 25 years ago to be the theoretically best explosive. Hexanitrohexaazaisowurtzitane (CL-20) later proved to be 20% better than octogen and 6% better than hexanitrobenzene. In the early 1990s, FOA (National Defence Research Establishment, Sweden) synthesized CL-20, enabling Sweden to purchase it from the United States. In 1995, an effective synthesis for ammonium dinitramide (ADN) was found. ADN gives much lower signature in rockets than ammonium perchlorate (AP), higher performance, and low environmental impact. Diaminodinitroethene (FOX-7) is a high explosive with lower sensitivity than TNT and similar performance to hexogen (RDX). N-guanylurea dinitramide (FOX-12) has properties similar to NC but is very insensitive and inherently more thermally stable. An FOI effort to synthetize new high energy density materials started with tetrahedral tetraazatetrahedrane (N4), sponsored by the U. S. DoD/DARPA. This nonnatural substance was modeled by numerical quantum mechanics, and promises to have three to four times the energy of octogen. So far, the existence of this molecule has not been verified; but efforts continue. Other nitrogen clusters, such as N8 or polymeric Nx, promise even higher yields. The pentazolate ion (N−5) was successfully made at FOI by laser synthesis. With the N+5 counterion, synthesized by the U. S. Air Force Research Laboratory, it could form a very energetic all-nitrogen molecule. The step in energy density from octogen to N4 is much greater than the change from black powder to high explosives, such as picric acid or trinitrotoluene, occurring in the 1870s. That change most certainly caused a complete revolution in warfare methods and weapons technology.
CATALYTIC IGNITION OF COLD HYDROGEN/OXYGEN MIXTURES FOR SPACE PROPULSION APPLICATIONS
217-230
10.1615/IntJEnergeticMaterialsChemProp.2012004877
Rachid
Amrousse
University of Chouaib Doukkali, Faculty of Sciences, 24000 El Jadida, Morocco
S.
Keav
Institut des Milieux et des Materiaux de Poitiers (IC2MP), University of Poitiers, 86022 Poitiers Cedex, France
Yann
Batonneau
CNRS UMR 7285, IC2MP, University of Poitiers, France
Charles J.
Kappenstein
Université de Poitiers, CNRS, IC2MP, Poitiers, 86073, France
M.
Theron
French Space Agency, Centre National d'Etudes Spatiales (CNES), 91023 Evry Cedex, France
P.
Bravais
Air Liquide, Division des Techniques Avancees, 38360 Sassenage, France
catalytic ignition
cold mixtures
monolithic catalysts
An experimental bench test was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen mixtures at low temperature by injection of cold gas mixtures on the catalytic microreactor. The selected supports for this study were cylindrical monoliths; i.e., cordierite honeycomb (600 channels per square inch) manufactured by CTI Company (Ceramiques & Techniques Industrielles). These materials were coated with porous γ-alumina to increase their specific surface area, and then impregnated by different metal precursors (Ir, Rh, Pt, and Ir−Rh). The premix gas reacted with the catalyst surface upon arrival in the combustion chamber. The first results led to a primary selection of different catalysts that allowed comparison with the different active phases. Based on the maximum temperature reached by the gas flow after a given time, we can sort the active phases as follows: Ir > Ir−Rh > Pt > Rh.
SYNTHESIS OF NANO-NICKEL-COATED MICRO-ALUMINUM AND THERMAL REACTIVITY OF ALUMINUM/NICKELSTANNIC-OXIDE THERMITE
231-243
10.1615/IntJEnergeticMaterialsChemProp.2012004927
Yi
Wang
School of Materials Science and Engineering, North University of China, Taiyuan 030051, People's Republic of China
Xiaolan
Song
School of Environment and Safety Engineering, North University of China, Taiyuan 030051, People's Republic of China
Wei
Jiang
National Special Superfine Powder Engineering Research Center, Nanjing University of Science & Technology, Nanjing, 210094, China
Guodong
Deng
National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
Xiaode
Guo
National Special Superfine Powder Engineering Research Center, Nanjing University of Science & Technology
Hongying
Liu
National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
Fengsheng
Li
National Special Superfine Powder Engineering Research Center, Nanjing University of Science & Technology, Nanjing, 210094, China
thermite reaction
Al-based composites
surface coating
impact ignition
The displacement method was employed to modify the surface of micron Al on which a layer of Ni nanoparticles were coated. NH4F acted as a key that enabled the displacement reaction to occurr. Al/Ni composites (with different coating percentage) were mixed with SnO2 and the mixtures were used as thermites. The thermite reaction of Al/Ni−SnO2 was investigated. For reactions between Al/Ni and SnO2, the onset temperature was lowered and the reaction heat remarkably increased compared with the Al−SnO2 reaction. Thermites Al−SnO2 and Al/Ni−SnO2 were heated simultaneity to 1020° C. The heated residues were investigated by scanning electron microscope, energy-dispersive spectroscopy, and x-ray diffraction analyses. Residue of raw Al manifested hollow shells composed of Al, α-Al2O3, and [θ ]-Al2O3; residue of Al/Ni exhibited broken fragments and bulk sinters consisting of α-Al2O3, AlN, [θ ]-Al2O3, and faint NiO.
CHARACTERIZATION AND DECOMPOSITION OF AMMONIUM DINITRAMIDE AS LIQUID PROPELLANT
245-257
10.1615/IntJEnergeticMaterialsChemProp.2012005172
Rachid
Amrousse
University of Chouaib Doukkali, Faculty of Sciences, 24000 El Jadida, Morocco
S.
Royer
Institut de Chimie des Milieux et des Materiaux (IC2MP), University of Poitiers, 86022 Poitiers, France
S.
Laassiri
Institut de Chimie des Milieux et des Materiaux (IC2MP), University of Poitiers, 86022 Poitiers, France; Department of Mining, Metallurgical and Materials Engineering (DMMME), University Laval, Quebec, Canada
binary ADN
ternary ADN-fuel
decomposition
Binary ammonium dinitramide (ADN) and ternary AND−fuel aqueous mixtures have been prepared. Two series of ternary mixtures have been synthesized with methanol and ethanol as fuels with stoichiometric fuel contents. Thermal and catalytic decomposition process of the prepared solutions has been analyzed. For binary ADN aqueous solutions, the thermal decomposition starts only once water has been fully vaporized and the oxidizer is in a liquid state. The influence of the fuel depends strongly on the oxidizer. Methanol and ethanol are vaporized before the decomposition, leading to results close to those observed for binary mixtures. ADN-based solutions display the highest catalytic effect with a temperature decrease of about 100° C.
IGNITION AND COMBUSTION STUDIES OF HETEROGENEOUS UDMH-RFNA GEL PROPELLANTS
259-275
10.1615/IntJEnergeticMaterialsChemProp.2012005238
Mohan
Varma
Department of Space Engineering and Rocketry, Birla Institute of Technology, Mesra, Ranchi, 835215, India
B. V. S.
Jyoti
Birla Institute of Technology, Ranchi, India
metalized liquid propellant
methyl cellulose
twin-jet combustor
temperature profile
rheological behavior
Advanced gel propulsion systems are being designed and developed for use in volume-limited space vehicles and advanced missile interceptors where safety, energy management, high performance, and efficient packing are the main concerns. Gelled propellants utilized in such a propulsion device are very delicately balanced systems and exhibit a complex ignition, combustion, and rheological behavior. The ignition and combustion characteristics of such heterogeneous systems have to be precisely understood to design a suitable injector and combustion chamber of the rocket motor to achieve a desired level of performance and combustion efficiency. An experimental investigation on ignition and combustion characteristics of UDMH gelled with high-substitution methyl cellulose as fuel and RFNA as oxidant has been carried out with and without metal additives, using a conventional ignition-delay tester and a customized twin-jet combustor. The ignition and combustion behavior of the gelled systems injected through a single-element injector has also been investigated. Preignition, ignition, and postignition temperature profiles close to the impingement point of the respective jets in a specially designed twin-jet combustor have been recorded using a suitable thermocouple and precision recording system. It has been observed that gels show lower ignition delay than the parent hypergolic system, however, a marginal increase is recorded in the case of metalized systems. The rheological characterization of the fuel gel has been conducted in a wide range of shear rate (10−2−106 s−1) and it has been found to be thixotropic in nature with viscosity values drastically falling with shear rate.