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Shimpei Togo - One of the best experts on this subject based on the ideXlab platform.
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influence of iron oxide on thermal decomposition behavior and burning characteristics of ammonium nitrate ammonium perchlorate based Composite Propellants
Combustion and Flame, 2018Co-Authors: Makoto Kohga, Shimpei TogoAbstract:Abstract The thermal decomposition behavior and burning characteristics of ammonium nitrate(AN)/ammonium perchlorate(AP) Propellants supplemented with Fe2O3 were investigated. Based on these data, the performance differences between the Propellants with Fe2O3 and those without Fe2O3 were investigated to reveal the influence of Fe2O3 on the thermal decomposition behavior and burning characteristics of AN/AP-based Composite Propellants. TG-DTA showed the peak temperature and temperature range of thermal decomposition due to AN decomposition to be independent of the presence of Fe2O3. The peak and the offset temperature of thermal decomposition due to AP decomposition decreased owing to the addition of Fe2O3, while the onset temperature did not vary. The burning rate of the AN/AP propellant was increased by the addition of Fe2O3; the effect of Fe2O3 on increasing the burning rate was influenced by the type of oxidizer, AP content in the oxidizer (ξ), and AP size. Furthermore, Fe2O3 allowed the suppression of the remarkable heterogeneity of the combustion wave of the AN/AP propellant without Fe2O3. The ignitability of the AN/AP propellant was improved by the addition of Fe2O3, except for the propellant with a ξ of 0.4. The cause of depressed ignitability by the addition of Fe2O3 for the propellant with a ξ of 0.4 is discussed based on thermogravimetry-differential thermal analysis, the visual observations of the unignited propellant surfaces, and the decomposition phenomena of the Propellants using a high-temperature observation equipment. A large quantity of AN remained on the surface of the unignited propellant at 0.5 MPa. The cause of the depressed ignitability is that AN, AP, and HTPB do not simultaneously decompose and as a result AN remains on the burning surface. Thus, the burning surface of AN did not regress simultaneously with the burning surface of the AP-filled region, the matrix of AP, and HTPB.
D. B. Lempert - One of the best experts on this subject based on the ideXlab platform.
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Thermochemical and Energy Characteristics of Dimers of Terfurazanoazepines
Combustion Explosion and Shock Waves, 2020Co-Authors: D. B. Lempert, A I Kazakov, A. V. Nabatova, D. V. Dashko, A. I. Stepanov, G. V. Shilov, S M AldoshinAbstract:The heat of combustion and the enthalpy of formation of 7,7′-bis(terfurazan[3,4- b :3,4′- d :3″,4″- f ]azepine (I) and 1,1′-dioxide-7,7′-bis(terfurazan[3,4- b :3,4′- d :3″,4″- f ] azepine (II), were experimentally determined. Product I was studied by X-ray diffraction analysis, and its crystallographic characteristics were determined. The efficiency of using compounds I and II as components of solid Composite Propellants was analyzed, and the type of compositions in which they are more effective than HMX was determined.
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Thermochemical and Energy Characteristics of DAzFF and AzNTF
Combustion Explosion and Shock Waves, 2019Co-Authors: D. B. Lempert, A I Kazakov, V. S. Sannikov, A. V. Nabatova, D. V. Dashko, A. I. StepanovAbstract:The heat of combustion and the standard enthalpy of formation of 3,4-bis(4-azidofurazan-3-yl)furoxan (DAzFF) and 4-azido-4″-nitro-3,3′:4′,′3′-terfurazan (AzNTF) were experimentally determined. Thermodynamic analysis was performed to investigate the efficiency of these compounds as potential components of metal-free solid Composite Propellants based on an active binder with the possibility of introducing an additional small amount of oxidizer with a high oxygen content, e.g., ammonium perchlorate.
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Energy Potential of Some Hypothetical Derivatives of Tetrazole as Components of Solid Composite Propellants
Combustion Explosion and Shock Waves, 2019Co-Authors: I. Yu. Gudkova, V. P. Kosilko, D. B. LempertAbstract:The energy potential of compositions based on a number of hypothetical tetrazole derivatives with a very high mass content of nitrogen (73-75%) have been studied by thermochemical calculations. Quantitative dependences of the energy parameters of solid Composite Propellants on the nature of the high-enthalpy polynitrogen oxidizer and the presence of metal in the composition have been determined.
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polynitromethyl derivatives of furazano 3 4 e di 1 2 4 triazolo 4 3 a 3 4 c pyrazine as components of solid Composite Propellants
Russian Chemical Bulletin, 2018Co-Authors: D. B. Lempert, A B SheremetevAbstract:The energetic potential of solid Composite Propellants (SCP) with furazano[3,4-e]di([1,2,4]- triazolo)[4,3-a:3′,4′-c]pyrazine including trinitromethyl (C(NO2)3), fluorodinitromethyl (CF(NO2)2), and (difluoroamino)dinitromethyl (C(NF2)(NO2)2) groups was estimated based on thermochemical calculations. It was shown that C(NO2)3 and C(NF2)(NO2)2 derivatives can constitute the basis of metal-free compositions of SCP with a specific impulse from 251 to 263 s, i.e., comparable or superior in efficiency to HMX-based Propellants.
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energetic abilities of nitro derivatives of isomeric pyrazol 3 yl tetrazoles as components of solid Composite Propellants
Russian Chemical Bulletin, 2018Co-Authors: D. B. Lempert, A I Kazakov, S I Soglasnova, I L Dalinger, A B SheremetevAbstract:Theoretical estimation of the efficiency factors of solid Propellants whose components are CHNO compounds designed from various combinations of four structural motifs, namely pyrazole and tetrazole rings, nitro group, and trinitromethyl moiety, was performed. The positional isomerism was shown to have effect on the properties of the compounds and the energy characteristics of solid Composite Propellants (SCPs) on their basis. The use of these components in metal-free SCP compositions can allow one to achieve a specific impulse of 258–263 s, neither toxic HCl nor condensed products being produced upon their combustion, i.e., they are superior in energy and environmental indices to SCP formulations based on ammonium perchlorate.
Makoto Kohga - One of the best experts on this subject based on the ideXlab platform.
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influence of iron oxide on thermal decomposition behavior and burning characteristics of ammonium nitrate ammonium perchlorate based Composite Propellants
Combustion and Flame, 2018Co-Authors: Makoto Kohga, Shimpei TogoAbstract:Abstract The thermal decomposition behavior and burning characteristics of ammonium nitrate(AN)/ammonium perchlorate(AP) Propellants supplemented with Fe2O3 were investigated. Based on these data, the performance differences between the Propellants with Fe2O3 and those without Fe2O3 were investigated to reveal the influence of Fe2O3 on the thermal decomposition behavior and burning characteristics of AN/AP-based Composite Propellants. TG-DTA showed the peak temperature and temperature range of thermal decomposition due to AN decomposition to be independent of the presence of Fe2O3. The peak and the offset temperature of thermal decomposition due to AP decomposition decreased owing to the addition of Fe2O3, while the onset temperature did not vary. The burning rate of the AN/AP propellant was increased by the addition of Fe2O3; the effect of Fe2O3 on increasing the burning rate was influenced by the type of oxidizer, AP content in the oxidizer (ξ), and AP size. Furthermore, Fe2O3 allowed the suppression of the remarkable heterogeneity of the combustion wave of the AN/AP propellant without Fe2O3. The ignitability of the AN/AP propellant was improved by the addition of Fe2O3, except for the propellant with a ξ of 0.4. The cause of depressed ignitability by the addition of Fe2O3 for the propellant with a ξ of 0.4 is discussed based on thermogravimetry-differential thermal analysis, the visual observations of the unignited propellant surfaces, and the decomposition phenomena of the Propellants using a high-temperature observation equipment. A large quantity of AN remained on the surface of the unignited propellant at 0.5 MPa. The cause of the depressed ignitability is that AN, AP, and HTPB do not simultaneously decompose and as a result AN remains on the burning surface. Thus, the burning surface of AN did not regress simultaneously with the burning surface of the AP-filled region, the matrix of AP, and HTPB.
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thermal decomposition behaviors and burning characteristics of an rdx based Composite Propellants supplemented with mno2 and fe2o3
Journal of Energetic Materials, 2015Co-Authors: Makoto Kohga, Tomoki NayaAbstract:Ammonium nitrate (AN)-based Composite Propellants have gained popularity because of the clean burning nature of AN as an oxidizer. However, such Propellants have several disadvantages such as poor ignition and low burning rate. The burning characteristics of the AN propellant were improved when a portion of this propellant was replaced by an energetic material and the addition of a catalyst. In this study, RDX (1,3,5-trinitroperhydro-1,3,5-triazine) was used as the energetic material, and Fe2O3 and MnO2 were used as catalysts. The burning characteristics of the AN/RDX Propellants supplemented with catalysts were investigated, and the effects of the replacement of AN by RDX and the catalyst addition were evaluated.
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burning characteristics of ammonium nitrate based Composite Propellants supplemented with mno2
Propellants Explosives Pyrotechnics, 2013Co-Authors: Tomoki Naya, Makoto KohgaAbstract:Ammonium nitrate (AN)-based Composite Propellants have several major problems, namely, a low burning rate, poor ignitability, low energy, and high hygroscopicity. The addition of a burning catalyst proved to be effective in improving the burning characteristics of AN-based Propellants. In this study, the burning characteristics of AN-based Propellants supplemented with MnO2 as a burning catalyst were investigated. The addition of MnO2 is known to improve the ignitability at low pressure. The most effective amount of MnO2 added (ξ) for increasing the burning rate is found to be 4 %. The increasing ratio with ξ is virtually independent of the burning pressure and the AN content. However, the pressure exponent unfortunately increased by addition of MnO2. The apparent activation energy of the thermal decomposition for AN and the propellant is decreased by addition of MnO2. From thermal decomposition kinetics it was found that MnO2 could accelerate the thermal decomposition reaction of AN in the condensed phase, and therefore, the burning characteristics of the AN-based propellant are improved.
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burning characteristics of ammonium nitrate based Composite Propellants with a hydroxyl terminated polybutadiene polytetrahydrofuran blend binder
International Journal of Aerospace Engineering, 2012Co-Authors: Makoto Kohga, Tomoki Naya, Kayoko OkamotoAbstract:Ammonium-nitrate-(AN-) based Composite Propellants prepared with a hydroxyl-terminated polybutadiene (HTPB)/polytetrahydrofuran (PTHF) blend binder have unique thermal decomposition characteristics. In this study, the burning characteristics of AN/HTPB/PTHF Propellants are investigated. The specific impulse and adiabatic flame temperature of an AN-based propellant theoretically increases with an increase in the proportion of PTHF in the HTPB/PTHF blend. With an AN/HTPB propellant, a solid residue is left on the burning surface of the propellant, and the shape of this residue is similar to that of the propellant. On the other hand, an AN/HTPB/PTHF propellant does not leave a solid residue. The burning rates of the AN/HTPB/PTHF propellant are not markedly different from those of the AN/HTPB propellant because some of the liquefied HTPB/PTHF binder cover the burning surface and impede decomposition and combustion. The burning rates of an AN/HTPB/PTHF propellant with a burning catalyst are higher than those of an AN/HTPB propellant supplemented with a catalyst. The beneficial effect of the blend binder on the burning characteristics is clarified upon the addition of a catalyst. The catalyst suppresses the negative influence of the liquefied binder that covers the burning surface. Thus, HTPB/PTHF blend binders are useful in improving the performance of AN-based Propellants.
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burning characteristics of ammonium nitrate based Composite Propellants supplemented with ammonium dichromate
Propellants Explosives Pyrotechnics, 2009Co-Authors: Makoto Kohga, Saeko NishinoAbstract:Ammonium nitrate (AN)-based Composite Propellants have attracted much attention, primarily because of the clean burning nature of AN as an oxidizer. However, such Propellants have some disadvantages such as poor ignition and low burning rate. Ammonium dichromate (ADC) is used as a burning catalyst for AN-based Propellants; however, the effect of ADC on the burning characteristics has yet to be sufficiently delineated. The burning characteristics of AN/ADC Propellants prepared with various contents of AN and ADC have been investigated in this study. The theoretical performance of an AN-based propellant is improved by the addition of ADC. The increase in the burning rate is enhanced and the pressure deflagration limit (PDL) becomes lower with increasing amount of ADC added. The increasing ratio of the burning rate with respect to the amount of ADC is independent of the AN content and the combustion pressure. The optimal amount of ADC for improving the burning characteristics has been determined.
Francisco Brójo - One of the best experts on this subject based on the ideXlab platform.
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Theoretical analysis of ammonium-perchlorate based Composite Propellants containing small size particles of boron
Energy Procedia, 2017Co-Authors: Paulo Alexandre Rodrigues De Vasconcelos Figueiredo, Francisco BrójoAbstract:Abstract One of the main goals for the scientific/ military rocket industry is to increase the operational burning time, thus the specific impulse. New homogeneous and heterogeneous Propellants were tested and metallic fuels were added in the mixture to obtain best performance. To study heterogeneous propellant, containing large amount of fine boron and ammonium perchlorate, it is appropriate to estimate the combustion products to evaluate/obtain the values of the specific impulse, density, Mach number and mass flow of the mixture. Several Composite propellant mixtures, ammonium perchlorate, nitramides (RDX – Cyclotrimethylene trinitramide), were defined with or without addiction of small particles of Boron and modeled. The energetic properties of boron and progress of boron particles on the burning surface of the ammonium perchlorate based Composite Propellants was modeled used a numerical algorithm. This paper reports the analysis of the influence of boron in the performance parameters for ammonium perchlorate based Composite Propellants.
Paulo Alexandre Rodrigues De Vasconcelos Figueiredo - One of the best experts on this subject based on the ideXlab platform.
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Theoretical analysis of ammonium-perchlorate based Composite Propellants containing small size particles of boron
Energy Procedia, 2017Co-Authors: Paulo Alexandre Rodrigues De Vasconcelos Figueiredo, Francisco BrójoAbstract:Abstract One of the main goals for the scientific/ military rocket industry is to increase the operational burning time, thus the specific impulse. New homogeneous and heterogeneous Propellants were tested and metallic fuels were added in the mixture to obtain best performance. To study heterogeneous propellant, containing large amount of fine boron and ammonium perchlorate, it is appropriate to estimate the combustion products to evaluate/obtain the values of the specific impulse, density, Mach number and mass flow of the mixture. Several Composite propellant mixtures, ammonium perchlorate, nitramides (RDX – Cyclotrimethylene trinitramide), were defined with or without addiction of small particles of Boron and modeled. The energetic properties of boron and progress of boron particles on the burning surface of the ammonium perchlorate based Composite Propellants was modeled used a numerical algorithm. This paper reports the analysis of the influence of boron in the performance parameters for ammonium perchlorate based Composite Propellants.