Begell House Inc.
International Journal of Energetic Materials and Chemical Propulsion
IJEMCP
2150-766X
6
2
2007
AGGLOMERATION AND IGNITION OF ALUMINUM PARTICLES COATED BY NICKEL
143-151
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.10
Valery
Rosenband
Faculty of Aerospace Engineering, Technion- Israel Institute of Technology, Haifa 32000, Israel
Alon
Gany
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology,
Haifa, 3200003, Israel
Agglomeration and ignition of aluminum particles coated by nickel have been investigated. A controlled chemical deposition technique for coating aluminum particles by nickel was developed. Coated Al particles with nickel content from 1 to 15 wt% were produced. Investigations of the behavior of the nickel-coated Al particles during their heating in nitrogen and air were carried out. It was shown that, while uncoated Al particles agglomerate during heating, the coated aluminum particles do not agglomerate and remain in a powder form. Also, experiments demonstrated better ignitability of the nickel-coated Al particles in comparison with regular Al particles, where ignition temperature depends on the initial nickel content. Improvement of ignitability of the coated Al particles is explained by the exothermic reaction between nickel and aluminum and by thermal and mechanical properties of the formed intermetallics.
MODIFIED BURNING RATE SPECTRUM & COMBUSTION MECHANISM OFTETRA-OLGAP
153-169
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.20
Sumito
Togo
Institute of Space & Astronautical Science/Japan Aeropace Exploration, Agency, JAPAN
Kiyokazu
Kobayashi
Institute of Space & Astronautical Science/Japan Aeropace Exploration Agency (JAXA), Japan
Toru
Shimada
ISAS, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan
Yasushi
Niimi
NOF Corporation, JAPAN
Yoshio
Seike
NOF Corporation, JAPAN
Makihito
Nishioka
University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
Keiichi
Hori
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration
Agency (JAXA), Sagamihara, Kanagawa, 252-5210, Japan
GAP
burning rate
firing test
C* efficiency
combustion model
Attempts were made to extend the burning rate spectrum of glycidyl azide polymer (GAP) towards both upper and lower sides. Nano-sized aluminum and carbon nanofibres (CNF) were used to enhance the burning rate of GAP, and polyethylene glycol (PEG) was used to lower the burning rate. PEG addition is very effective and burning rate is lowered below 4mm/s even at 10MPa. Mechanical properties were also evaluated and shown to be good enough for practical use. Static firing tests of GAP as a gas generator for hybrid rockets were successfully performed in small size rocket motors, and the detail of them are presented and discussed. Combustion mechanism of cured tetra-ol GAP based upon the Beckstead model was developed using the results of fine thermocouple temperature measurement. Some modifications are made to adjust experimental results.
WHY AND HOW TYPE OF PASSIVATION LAYER AFFECTS THE PROPERTIES OF ALUMINUM NANOPOWDERS FOR ENERGETIC APPLICATIONS
171-180
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.30
Alexander
Gromov
Fraunhofer Institute for Chemical Technology, D-76327 Pfinztal (Berghausen), Germany
Ulrich
Forter-Barth
Fraunhofer Institute for Chemical Technology, D-76327 Pfinztal (Berghausen), Germany
Ulrich
Teipel
Nuremberg University of Technology Georg-Simon-Ohm, 90121, Nuremberg, Germany
Results of DTA-TG-investigations and chemical analysis of electro-exploded aluminum nanopowders, coated and/or passivated by the reactive reagents: nitrocellulose (NC), ethanol, Teflon, oleic (C17H33COOH) and stearic (C17H35COOH) acid, amorphous boron, nickel, air, and ALEX (for comparison) are shown. The disadvantages of aluminum nanopowders, passivated by air and covered by a thick oxide layer, which affects adversely their energetic properties, are their low metal content and their low stability to further oxidation during storage. Non-oxide coatings, i.e., aluminum nanopowders with a protecting surface are expected to have improved material properties. The kinetics of the interaction of aluminum nanopowders with nitrogen, air, and in water are described.
FUTURE CHEMICAL PROPELLANTS FOR SPACE, DEFENSE, AND COMMERCIAL APPLICATIONS
181-196
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.40
Christian
Perut
Groupe Recherche Propulsion, SNPE Matériaux Energétiques CRB, France
Research and development into new solid propellants is usually granted in order to satisfy defense requirements. The energetic products most frequently mentioned in formulation studies are fillers such as ADN (ammonium dinitramide), nitramines, RDX and HMX, HNIW (hexanitro-hexaazaisowurtzitane), HNF (hydrazinium nitroformate), and binders such as GAP (glycidyl azide polymer), PGLYN (polyglycidyl nitrate) and PNMMO (polynitratomethyl-methyl oxetane). The use of GAP and HNIW brings about an increase in volumetric specific impulse of 12% compared to a current XLDB, formulated with an inert polymer and loaded with RDX. The HNIW-based propellants have been assessed successfully in 10-kg grains. They are considered to be suitable for introduction in the development of motors for tactical missiles. The longer-term studies are centred on synthesis and the use of heterocyclic molecules such as the furazanes, furoxanes, tetrazines, etc. For launcher boosters, the main objectives are cost reduction, increased performance and reliability. A first generation of propellant composition could be developed in the near future, by replacing part of the AP content with a different energetic component.
Hydrazine has been used as a monopropellant since 1958. It has the disadvantage of being extremely toxic, and this has encouraged research into new compositions. These compositions comprise an ionic aqueous solution of an oxidizer and reducer. The tested oxidizers are principally HAN, ADN and HNF. There has recently been renewed interest in the use of hydrogen peroxide for space applications. Bi-liquid motors that use methane are of particular interest.
Particularly noticeable among the compositions with long-term potential is liquid hydrogen gelled through methane crystals, for example, and "High Energy Density Materials" or HEDM. For these last products, energy is supplied principally, and sometimes exclusively, by the metastability of the molecules. This new concept is envisaged for both solid and liquid propulsion.
For many years, SNPE Matériaux Energétiques has been developing compositions for applications, which are outside the field of propulsion. Vehicle safety airbags is one of such applications, which has developed very fast since the mid-1990s. The gases needed to inflate the airbag are supplied from a gas generator that contains propellant grains. The propellant used in the airbag applications must satisfy certain specifications mainly including non-toxicity of gas, moderate combustion temperature, and excellent thermal stability. SNPE Matériaux Energétiques has used its experience with solid propellants to suggest an adapted composition for such propellants to its industrial partner Autoliv Inc. In this particular propellant composition, a monolithic grain is adopted. A continuous manufacturing process using a twin-screw has been chosen for propellant production, which is suitable for large scale production of such propellant.
PyroAlliance, a subsidiary of SNPE Matériaux Energétiques, is developing onboard energetic equipments such as micro-thrusters and actuators. A new concept of actuator, is currently being developed, which is based on a hybrid design. The oxidizer used in this design can be a liquid or gaseous mixture containing oxygen-rich chemicals. This design is less cumbersome than the classic systems based on use of pressurised vessels.
EXAMINATION OF AP/KN COMPOSITE PROPELLANT THERMAL WAVE STRUCTURE UNDER STEADY-STATE BURNING
197-212
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.50
Vladica S.
Bozic
Ministry of Environmental Protection, Omladinskih brigada 1, Novi Beograd,
11070, Serbia
Marko V.
Milos
Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade 35
D. D.
Blagojevic
Faculty of Mechanical Engineering, 27 marta 80, 11000 Belgrade, Serbia and Montenegro
Boris S.
Jankovski
Veda, Aleksandar Martukov 45, 1000 Skopje, Macedonia
microthermocouple technique
AP/KN composite rocket propellant
A formulation of composite propellant based on modified PVC binder has been produced, such that part of the ammonium perchlorate has been replaced with potassium nitrate. This resulted in improved environment behavior at the expense of unusual changes in burning rate at different pressures, with alarmingly high-pressure exponent during burning at pressures over 2 MPa. The aim of this investigation is to examine processes in the combustion wave near the burning surface during combustion. A technique based on fine-wire thermocouples embedded in the propellant has been used to accomplish precision measurement of temperature profiles through the entire flame zone of the solid propellants. This paper reports the technique and measurement results.
PHYSICAL AND CHEMICAL PROCESSES GOVERNING THE COMBUSTION OF BINARY COMPOSITIONS OF AMMONIUM DINITRAMIDE WITH GLYCIDYLAZIDEPOLYMER
213-228
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.60
Valery
Sinditskii
Mendeleev University of Chemical Technology
Viacheslav Yu.
Egorshev
Department of Chemical Engineering, Mendeleev University of Chemical Technology, 9 Miusskaya Sq., 125047, Moscow, Russia
Anton I.
Levshenkov
Department of Chemical Engineering, Mendeleev University of Chemical Technology
Maxim V.
Berezin
Department of Chemical Engineering, Mendeleev University of Chemical Technology
The paper presents a study of the burning behavior and flame structure of compositions consisting of ammonium dinitramide (ADN) and glycidylazidepolymer (GAP). Unlike neat ADN and GAP, the ADN/GAP binary mixtures appeared to burn steadily within the whole pressure interval, showing no breaks on the burning rate vs. pressure dependences. In the low-pressure area, the mixtures burn with rates less than those of pure ADN and exceed it as pressure grows above 10 MPa. In the whole pressure interval, the mixtures burn with the rates higher than those of pure GAP. It was determined on the basis of flame structure investigation that the surface temperature of ADN/GAP mixtures is controlled by the dissociation reaction of ammonium nitrate (AN) formed in the condensed phase during ADN decomposition. Physical and chemical processes responsible for the observed combustion behavior of the mixtures are discussed.
THE ROLE OF ADDITIVES IN COMBUSTION MECHANISM OF AMMONIUM NITRATE
229-253
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.70
Valery
Sinditskii
Mendeleev University of Chemical Technology
Viacheslav Yu.
Egorshev
Department of Chemical Engineering, Mendeleev University of Chemical Technology, 9 Miusskaya Sq., 125047, Moscow, Russia
Anton I.
Levshenkov
Department of Chemical Engineering, Mendeleev University of Chemical Technology
Valery V.
Serushkin
Department of Chemical Engineering, Mendeleev University of Chemical Technology, Moscow, 125047, Russia
Ammonium nitrate
combustion mechanism
role of additives
surface temperature
This paper presents an analysis of the observable combustion behavior of Ammonium Nitrate (AN) mixtures with different additives, fuels, and explosives. On the basis of flame structure investigation by fine tungsten-rhenium thermocouples, it was determined that the surface temperature of AN is controlled by the dissociation reaction of the salt occurring at the surface. Results obtained from experimental analysis have indicated that the leading reaction of combustion of AN doped with additives proceeds in the condensed phase up to pressures of 20−30 MPa. In this paper, a possible reason for the inability of pure AN to burn has been suggested and the role of additives in the combustion mechanism is also discussed.
DECOMPOSITION AND PERFORMANCEOFNEW HIGH NITROGEN PROPELLANTS AND EXPLOSIVES
255-268
10.1615/IntJEnergeticMaterialsChemProp.v6.i2.80
Bryce
Tappan
Los Alamos National Laboratory
Steven F.
Son
School of Aeronautics and Astronautics, Purdue University, West Lafayette,
Indiana, USA
Arif N.
Ali
Dynamic Experimentation Division, DX-2 Materials Dynamics Group Los Alamos National Laboratory, Los Alamos, NM USA 87545
David E.
Chavez
Dynamic Experimentation Division, DX-2 Materials Dynamics Group Los Alamos National Laboratory, Los Alamos, NM USA 87545
Michael A.
Hiskey
Dynamic Experimentation Division, DX-2 Materials Dynamics Group Los Alamos National Laboratory, Los Alamos, NM USA 87545
As of late, molecules with high nitrogen content have received increased attention, due in large part to their novel energetic materials properties. At the Los Alamos National Laboratory, we continue to pursue the development and characterization of new high-nitrogen materials for applications in a wide variety of fields. In this work, three molecules, triaminoguanidinium azotetrazolate (TAGzT), 3,6-bis-nitroguanyl-1,2,4,5-tetrazine, and its corresponding bis-triaminoguanidinium salt, are studied. All three molecules are high-nitrogen compounds with little or no oxygen; however, they retain energetic material properties as a result of their high heats of formation. Due to these features, the decomposition of this class of compounds has limited or no secondary oxidation reactions of carbon and hydrogen. Other materials discussed for comparison include 3,3'-azobis(6-amino-1,2,4,5-tetrazine)-mixed N-oxides (DAATO3.5) and 3,6-bis(1H-1,2,3,4-tetrazol-5-ylamino)-s-tetrazine (BTATz), and the nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The fact that many of these molecules approach 80% nitrogen content makes them potentially useful as gas generants or energetic materials with low flame temperatures, while simultaneously increasing the impulse of gun or rocket propellants.
The burning rate, flash pyrolysis (T-jump/FTIR spectroscopy), explosive sensitivity, and performance properties were determined. Some examples of interesting behaviors include TAGzT exhibiting one of the fastest low pressure burning rates yet measured for an organic compound, and 3,6-bis-nitroguanyl-1,2,4,5-tetrazine having one of the lowest pressure exponents yet measured for a pure organic compound.