Begell House Inc.
International Journal of Energetic Materials and Chemical Propulsion
IJEMCP
2150-766X
11
2
2012
GLYCIDYL AZIDE POLYMER AND POLYETHYLENE GLYCOL MIXTURES AS HYBRID ROCKET FUELS
97-106
10.1615/IntJEnergeticMaterialsChemProp.2012001456
Keiichi
Hori
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration
Agency (JAXA), Sagamihara, Kanagawa, 252-5210, Japan
Yuya
Nomura
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1, Yoshinodai, Sagamihara, Kanagawa, 229-8510, Japan
Koji
Fujisato
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo-Ku, Sagamihara, Kanagawa 252-5210, Japan
Takeshi
Yagishita
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1, Yoshinodai, Sagamihara, Kanagawa, 229-8510, Japan
Makihito
Nishioka
University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
Yutaka
Wada
Akita University, 1-1, Tegata, Gakuen-machi, Akita City, Akita, 010-8502, Japan
Motoyasu
Kimura
NOF Corporation, Yebisu Garden Place Tower, 20-3, Ebisu 4-chome, Shibuya-ku, Tokyo, 150-6019, Japan
glycidyl azide polymer (GAP)
poly ethylene glycol (PEG)
hybrid rocket
gas hybrid
traditional hybrid
regression rate
Two types of hybrid rocket motors that use mixtures of glycidyl azide polymer (GAP) and polyethelene glycol (PEG) as the solid fuel are proposed and the combustion characteristics are presented. GAP and PEG mixtures in which the PEG concentrations are lower than a critical value between 40 and 50 mass% can sustain self-combustibility and can be used as a solid fuel for gas hybrid rocket systems, while mixtures with higher PEG concentrations and without self-combustibility can be employed as a solid fuel for traditional hybrid rockets. Thrust control and tailoring using changes in both the oxidizer/fuel (O/F) ratio and grain composition were investigated for the gas hybrid system, and successful control was accomplished in experiments. Firing tests were conducted of a traditional hybrid rocket motor as functions of the oxygen mass flux and burning pressure. The effect of GAP is obvious, and GAP enhances the regression rates of the solid fuel grain, and an effect of pressure was also found. The distributed flame model is discussed briefly here to explain the regression rate increase by GAP.
EXPERIMENTAL INVESTIGATION OF METALIZED SOLID FUEL RAMJET COMBUSTOR
107-121
10.1615/IntJEnergeticMaterialsChemProp.2012001388
Shimon
Saraf
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
ramjet
solid fuel
aluminum powder
This article presents an experimental investigation of metalized and non-metalized solid fuel ramjet combustors. The research is motivated by previous theoretical studies that suggest metals such as aluminum, magnesium, and zirconium can provide much higher heat release per unit mass of air; hence, increasing the specific thrust (i.e., thrust per unit airflow rate) of the engine (in this study aluminum particles were added to the fuel). A hydrogen vitiated air heater was used to simulate in a static test facility the incoming air stagnation properties of about Mach 3 flight at sea level. Ignition and stable combustion of both metalized and non-metalized fuels have been achieved. The results show that the regression rate of the fuel containing aluminum particles is slightly higher, generating a higher fuel mass flow rate. The addition of aluminum particles has improved the specific thrust while decreasing the specific impulse, with a good correlation to the theoretical calculations.
NG PLASTICIZED PE−PCP BINDER-BASED ADVANCED SOLID ROCKET PROPELLANTS: STUDIES ON MECHANICAL PROPERTIES
123-134
10.1615/IntJEnergeticMaterialsChemProp.2012004717
Shrikant M.
Pande
High Energy Materials Research Laboratory (HEMRL), Defence Research and Development Organisation (DRDO)
Vaibhav S.
Sadavarte
High Energy Materials Research Laboratory, Pune, Maharashtra, 411021, India
Debdas
Bhowmik
High Energy Materials Research Laboratory, Pune, Maharashtra, 411021, India
Haridwar
Singh
High Energy Materials Research Laboratory, Pune 411 021; University of Hyderabad, Hyderabad
mechanical properties
tensile strength
percent elongation
modulus
glass transition temperature
The mechanical properties of solid rocket propellants play a vital role in the efficient functioning of rocket motors over a wide range of temperatures. A propellant grain must maintain its structural integrity during storage, handling, and various dynamic loads, such as acceleration during flight. The tensile strength, percentage elongation and elastic modulus are the inherent properties of the propellant and are more significant during the development of solid propellant for a particular mission. The polymeric binder largely determines the mechanical properties of the propellant. In this study, the mechanical properties of the cured prepolymer, cured nitroglycerin (NG) plasticized pentaerythritol−polycaprolactone prepolymer (PE−PCP) binder, and propellants have been evaluated at different temperatures. The glass transition temperatures (Tg) of these samples were also evaluated to study the effect of plasticization, isocyanate used as the curing agent, and the NCO:OH ratio. Propellant formulations for case-bonded applications having high plasticizer (Pl) to polymer (Po) ratio (Pl/Po > 2) containing solid energetic materials as ingredients were evaluated for their structural integrity by determining the mechanical properties at ambient (+27° C), cold (−40° C), and hot (+55° C) conditions. It has been observed that the tensile strength, percent elongation, and elastic modulus increase at the cold condition (−40° C) compared to the ambient and hot conditions. This distinctive characteristic of the propellant is due to the presence of highly plasticized prepolymer in the formulation.
INVESTIGATION OF NANOPOROUS SILICON−BASED ENERGETIC MATERIALS
135-148
10.1615/IntJEnergeticMaterialsChemProp.2012005344
Evgenia Golda
Fradkin
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Haifa, Israel ; Rafael - Advanced Defense Systems Ltd, Haifa, Israel
Alon
Gany
Faculty of Aerospace Engineering, Technion - Israel Institute of Technology,
Haifa, 3200003, Israel
nanoporous silicon
energetic materials
This work investigates energetic materials based on nanoporous silicon fuel impregnated with sodium perchlorate oxidizer. The nanoporous silicon samples were prepared by anodization of silicon in a hydrofluoric acid solution, and the influence of the electric current density on the nanoporous structure was studied. The impregnation process was investigated thoroughly in order to achieve optimized pore filling by the sodium perchlorate oxidizer. Thermal analysis using differential scanning calorimetry was performed in order to characterize the energetic reaction and compare between the different samples. Feasibility proof for an energetic reaction of nanoporous silicon impregnated with sodium perchlorate oxidizer was demonstrated by ignition of the samples on a hot plate.
EQUATIONS OF STATE OF SILICON, BORON, AND HALOGEN SPECIES FOR ACCURATE DETONATION CALCULATIONS
149-163
10.1615/IntJEnergeticMaterialsChemProp.2012005404
Leonard I.
Stiel
NYU Polytechnic School of Engineering, Six Metrotech Center, Brooklyn, New York 11201, USA
Ernest L
Baker
U.S. Army Armament Research, Development and Engineering Center (ARDEC), Picatinny, New Jersey 07806-5000, USA
D. J.
Murphy
U.S. Army Armament Research, Development and Engineering Center (ARDEC), Picatinny, New Jersey 07806-5000, USA
equation of state
detonation
chemistry
The combined effects aluminized explosives PAX-29, PAX-30, and PAX-42 developed by the U.S. Army Armament Research, Development and Engineering Center (ARDEC) have been demonstrated to achieve excellent metal pushing and high-blast energies in both cylinder test and warhead configurations The detonation behavior of additional explosive compositions is being investigated using the Jaguar thermochemical equation of state in conjunction with experimental data for these systems. For these studies, accurate equation of state parameters are required for a wide range of gaseous, liquid, and solid explosive components and reaction products. The Jaguar procedures include the capabilities to accurately calculate cylinder velocities and other detonation properties with an analytic cylinder test model. The analytic cylinder test model has been recently updated to include eigenvalue detonation theory and associated adiabatic expansion from the fully reacted Hugoniot weak point. The Jaguar property library has been expanded to include additional gaseous, liquid, and solid components and detonation products. New Exp-6 parameters for gaseous substances have been established by analyses of Hugoniot data for the actual species or for reactants which decompose into these compounds. Parameters for additional condensed species were also established from Hugoniot and volumetric data under shock compression conditions. Comparisons are performed with data for explosives and compounds containing the elements investigated to determine the accuracy of calculated detonation properties with the established equation of state parameters.
EXPERIMENTS IN DILUTED PREMIXED TURBULENT STAGNATION FLAMES FOR GAS-TURBINE ENGINE APPLICATIONS
165-180
10.1615/IntJEnergeticMaterialsChemProp.2012005213
Sean D.
Salusbury
Department of Mechanical Engineering, McGill University, Montreal, QC, H3A 2K6, Canada
Jeffrey M.
Bergthorson
Department of Mechanical Engineering, McGill University, Montreal, QC, H3A 2K6, Canada
turbulent premixed flame
flamelet
thin reaction zone
dilution
turbulent burning velocity
particle image velocimetry
Rayleigh scattering
In general, turbulent combustion in gas-turbine engines occurs under conditions at which the smallest turbulent eddies are assumed to be smaller than the flame thickness but larger than the inner-layer thickness: the so-called thin reaction-zone regime. This study demonstrates a bench-top experimental technique to investigate turbulent combustion properties in this important regime, where the burning velocity of a flame is assumed to be a function of the mixture's laminar flame speed, turbulence intensity, diffusion coefficients, and the mean flame curvature. Experimental observation of turbulent counterflow flames in this thin reaction zone will be used to investigate properties of turbulent combustion and to test the applicability of turbulent burning velocity predictions. High-blockage plates upstream of a high-contraction ratio contoured nozzle are used to generate high-turbulence intensities of 20−40% in premixed methane-air flames. The experimental method makes use of two laser diagnostic techniques: (a) particle image velocimetry to measure flow velocity and turbulence intensity; (b) planar Rayleigh scattering to measure progress variable and flame-front curvature. The measured burning velocities in the thin reaction-zone regime are then determined and compared to those predicted by a previously proposed correlation and by the flamelet model. Further, the burning velocities of methane-air flames are investigated with carbon dioxide dilution to investigate the effect of varying laminar flame speed independent of turbulence intensity. Intense turbulence will bring this study into the scope of gas-turbine engines and a compact experimental apparatus allows both higher experimental resolution and simulation at lower computational cost.
ELIMINATION OF RESIDUAL PROPELLANT GAS IN A GUN-LAUNCHED MISSILE CHAMBER WITH INERT GAS
181-195
10.1615/IntJEnergeticMaterialsChemProp.2012004973
Bin
Xu
School of Chemical Engineering
Zhi-Tao
Liu
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Dan-Dan
Ji
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Xin
Liao
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
Ze-Shan
Wang
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
flammability elimination
inert gas
combustibility analysis
explosion limit
propellant gas
Inert gas was added to a gun-launched missile chamber to eliminate the flammability hazard of residual propellant gases. The combustible gas contents of three types of propellants were calculated using a gas constitution model. Based upon this information, the flammability of the gases was analyzed. Considering CO2 as a fully reacted gas and assuming gas composition does not change during the mixing process of CO2 with propellant product gases, the quantities of CO2 required to change the combustible gas mixture to a nonflammable one were obtained. This information helps to solve practical engineering problems.