The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
D. B. Lempert - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Performance of Some Metals and Nonmetals in Solid Propellants for Rocket-Ramjet Engines
Combustion Explosion and Shock Waves, 2020Co-Authors: L. S. Yanovskii, V. V. Raznoschikov, I. S. Averkov, M. S. Sharov, D. B. LempertAbstract:A comparative evaluation of the use of various metals and nonmetals as fuel components of a solid propellant containing ammonium perchlorate as an oxidizer and rubber as a binder was performed using the flight range criterion of a rocket-Ramjet aircraft taking into account the expected completeness of combustion of individual components. The influence of the energetic properties of the propellant on the technical and economic characteristics and flight performance of the aircraft was also taken into account. The aircraft flight range was calculated by numerical integration of flight dynamics equations. Based on the results, it is recommended that a number of fuel components should be studied in more detail, in particular, for the purpose of the full or partial replacement of boron currently used in solid propellants for rocket-Ramjet Engines.
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synthesis and characterization of 3 5 fluorodinitromethyl 1h 1 2 4 triazol 3 yl 4 nitrofurazan a novel promising energetic component of boron based fuels for rocket Ramjet Engines
Chemistry-an Asian Journal, 2019Co-Authors: Aleksei B Sheremetev, Natali S Aleksandrova, Svyatoslav S Semyakin, Kyrill Yu Suponitsky, D. B. LempertAbstract:The synthesis of a new energetic 1,2,4-triazole compound bearing nitrofurazanyl and fluorodinitromethyl units, which may find use as a component for rocket Ramjet Engines (RRE), is described. The target product was prepared in a four-step process applying oxidation/nitration/decarboxylation/fluorination reactions and is fully characterized. Its density and structural features were uniquely determined by X-ray analysis. It is shown that replacing HMX with the compound of this study in boron-based fuels gives an increase in energy.
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Prospects for the use of diethynylbenzene as a fuel dispersant for rocket Ramjet Engines
Russian Chemical Bulletin, 2019Co-Authors: L. S. Yanovskii, D. B. Lempert, V. V. Raznoschikov, I. S. Averkov, I. N. Zyuzin, A. F. Zholudev, M. B. KislovAbstract:The applicability of 1,4-diethynylbenzene (DEB) as a dispersant of solid fuels was studied. The atmospheric flight ranges of an aircraft with a rocket Ramjet engine operating on fuels with DEB dispersant and wth high-enthalpy dispersants containing not only carbon and hydrogen, but also nitrogen and oxygen, were compared. Fuels with DEB are much more efficient in terms of this performance characteristic. The regularities of gasification of solid propellants comprising DEB, a binder, and ammonium perchlorate were studied experimentally. 1,4-Diethynylbenzene containing no oxidizing elements in the molecule can burn by itself due to the high enthalpy of formation (Δ H °_f) in the 2–6 MPa pressure range. The dependences of the combustion rate on the pressure and on binder and ammonium perchlorate contents were elucidated.
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Evaluation of Effectiveness of Solid Fuels Based on High Enthalpy Dispersants for Rocket Ramjet Engines
Russian Journal of Applied Chemistry, 2019Co-Authors: L. S. Yanovskii, D. B. Lempert, V. V. Raznoschikov, I. S. Aver’kovAbstract:The possibility of replacing the currently widely used ammonium perchlorate as an oxidizing agent (dispersant) in the composition of solid boron-containing fuels for aircraft with rocket Ramjet engine was considered by dispersants with reduced nitrogen and oxygen content with a high enthalpy of formation (more than 2 MJ kg^−1) and capable of gasifying solid fuels. The efficiency of fuels with high enthalpy dispersants was evaluated in an optimization setting according to the flight range criterion of the aircraft taking into account the complete combustion of fuel in the afterburner chamber. A number of the most effective dispersants were recommended for further study.
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Thermochemical and Energy Characteristics Di-, Tri-, and Tetra-Azido-Substituted Azines As Gasifying Agents of Solid Fuels for Ramjet Engines
Combustion Explosion and Shock Waves, 2019Co-Authors: D. B. Lempert, S. V. Chapyshev, A. I. Kazakov, N. A. Plishkin, A. V. Shikhovtsev, L. S. YanovskiiAbstract:A number of di-, tri-, and tetraazido-substituted azines as potential energetic dispersing agents of solid propellants for Ramjet Engines have been studied. The enthalpy of combustion and the enthalpy of formation of several azides (2,4,6-triazidopyrimidine, 2,4,6-triazidopyridine, 3,4,5-triazidopyridine-2,6-dicarbonitrile, and 3,4,5,6-tetraazidopyridine-2-carbonitrile) were experimentally determined. Eleven azides were compared with HMX in terms of the enthalpy of combustion in oxygen to CO_2 and water (in the case of the presence of hydrogen in the component), as well as in terms of the temperature of the products of adiabatic conversion of the investigated components due to the high enthalpy of formation in the absence of an external oxidizer and the amount of gases released in this process. The enthalpy of combustion of all the investigated azides burned in air was found to be significantly higher than that of HMX, and for seven of the azides studied, the combustion temperature is significantly higher. As regards the gas release volume (24–31 mol/kg), the azides are inferior to HMX (41.9 mol/kg). Based on the combination of properties, the investigated azides can be considered as promising dispersing agents of solid propellants for Ramjet Engines.
SERGEY MIHAYLOVICH FROLOV - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of the operation process and thrust performance of an air breathing pulse detonation engine in supersonic flight conditions
Russian Journal of Physical Chemistry B, 2011Co-Authors: V.s. Ivanov, SERGEY MIHAYLOVICH FROLOVAbstract:Multidimensional simulations of the unsteady gasdynamic flow in the duct of an air-breathing pulse detonation engine (ABPDE) operating on propane gas and the flow around it in supersonic flight at Mach numbers M of 3.0 and an altitude of 9.3 and 16 km are performed. It is shown that, at a length and diameter of the duct of 2.12 m and 83 mm, respectively, an ABPDE with an air intake and a nozzle can operate in a cyclic mode at a repetition frequency of 48 Hz, with a rapid deflagration-to-detonation transition (DDT) occurring at a distance of 5–6 combustion chamber diameters. To determine the thrust performance of the ABPDE in flight conditions, a series of working cycles were simulated with consideration given to the external flow around the engine. Calculations showed that the specific impulse of the ABPDE is approximately 1700 s. This value is much higher than the specific impulse typical of Ramjet Engines operating on conventional combustion (1200–1500 s) and substantially lower than the specific impulse obtained for the atmospheric conditions at sea level at zero flight velocity (∼2500 s).
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combustion explosion and shock waves numerical simulation of the operation process and thrust performance of an airbreathing pulse detonation engine in supersonic flight conditions
2011Co-Authors: V.s. Ivanov, SERGEY MIHAYLOVICH FROLOVAbstract:Multidimensional simulations of the unsteady gasdynamic flow in the duct of an airbreathing pulse detonation engine (ABPDE) operating on propane gas and the flow around it in supersonic flight at Mach numbers M of 3.0 and an altitude of 9.3 and 16 km are performed. It is shown that, at a length and diameter of the duct of 2.12 m and 83 mm, respectively, an ABPDE with an air intake and a nozzle can oper� ate in a cyclic mode at a repetition frequency of 48 Hz, with a rapid deflagrationtodetonation transition (DDT) occurring at a distance of 5-6 combustion chamber diameters. To determine the thrust performance of the ABPDE in flight conditions, a series of working cycles were simulated with consideration given to the external flow around the engine. Calculations showed that the specific impulse of the ABPDE is approximately 1700 s. This value is much higher than the specific impulse typical of Ramjet Engines operating on conven� tional combustion (1200-1500 s) and substantially lower than the specific impulse obtained for the atmo� spheric conditions at sea level at zero flight velocity (~2500 s).
V.s. Ivanov - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of the operation process and thrust performance of an air breathing pulse detonation engine in supersonic flight conditions
Russian Journal of Physical Chemistry B, 2011Co-Authors: V.s. Ivanov, SERGEY MIHAYLOVICH FROLOVAbstract:Multidimensional simulations of the unsteady gasdynamic flow in the duct of an air-breathing pulse detonation engine (ABPDE) operating on propane gas and the flow around it in supersonic flight at Mach numbers M of 3.0 and an altitude of 9.3 and 16 km are performed. It is shown that, at a length and diameter of the duct of 2.12 m and 83 mm, respectively, an ABPDE with an air intake and a nozzle can operate in a cyclic mode at a repetition frequency of 48 Hz, with a rapid deflagration-to-detonation transition (DDT) occurring at a distance of 5–6 combustion chamber diameters. To determine the thrust performance of the ABPDE in flight conditions, a series of working cycles were simulated with consideration given to the external flow around the engine. Calculations showed that the specific impulse of the ABPDE is approximately 1700 s. This value is much higher than the specific impulse typical of Ramjet Engines operating on conventional combustion (1200–1500 s) and substantially lower than the specific impulse obtained for the atmospheric conditions at sea level at zero flight velocity (∼2500 s).
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combustion explosion and shock waves numerical simulation of the operation process and thrust performance of an airbreathing pulse detonation engine in supersonic flight conditions
2011Co-Authors: V.s. Ivanov, SERGEY MIHAYLOVICH FROLOVAbstract:Multidimensional simulations of the unsteady gasdynamic flow in the duct of an airbreathing pulse detonation engine (ABPDE) operating on propane gas and the flow around it in supersonic flight at Mach numbers M of 3.0 and an altitude of 9.3 and 16 km are performed. It is shown that, at a length and diameter of the duct of 2.12 m and 83 mm, respectively, an ABPDE with an air intake and a nozzle can oper� ate in a cyclic mode at a repetition frequency of 48 Hz, with a rapid deflagrationtodetonation transition (DDT) occurring at a distance of 5-6 combustion chamber diameters. To determine the thrust performance of the ABPDE in flight conditions, a series of working cycles were simulated with consideration given to the external flow around the engine. Calculations showed that the specific impulse of the ABPDE is approximately 1700 s. This value is much higher than the specific impulse typical of Ramjet Engines operating on conven� tional combustion (1200-1500 s) and substantially lower than the specific impulse obtained for the atmo� spheric conditions at sea level at zero flight velocity (~2500 s).
L. S. Yanovskii - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Performance of Some Metals and Nonmetals in Solid Propellants for Rocket-Ramjet Engines
Combustion Explosion and Shock Waves, 2020Co-Authors: L. S. Yanovskii, V. V. Raznoschikov, I. S. Averkov, M. S. Sharov, D. B. LempertAbstract:A comparative evaluation of the use of various metals and nonmetals as fuel components of a solid propellant containing ammonium perchlorate as an oxidizer and rubber as a binder was performed using the flight range criterion of a rocket-Ramjet aircraft taking into account the expected completeness of combustion of individual components. The influence of the energetic properties of the propellant on the technical and economic characteristics and flight performance of the aircraft was also taken into account. The aircraft flight range was calculated by numerical integration of flight dynamics equations. Based on the results, it is recommended that a number of fuel components should be studied in more detail, in particular, for the purpose of the full or partial replacement of boron currently used in solid propellants for rocket-Ramjet Engines.
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Prospects for the use of diethynylbenzene as a fuel dispersant for rocket Ramjet Engines
Russian Chemical Bulletin, 2019Co-Authors: L. S. Yanovskii, D. B. Lempert, V. V. Raznoschikov, I. S. Averkov, I. N. Zyuzin, A. F. Zholudev, M. B. KislovAbstract:The applicability of 1,4-diethynylbenzene (DEB) as a dispersant of solid fuels was studied. The atmospheric flight ranges of an aircraft with a rocket Ramjet engine operating on fuels with DEB dispersant and wth high-enthalpy dispersants containing not only carbon and hydrogen, but also nitrogen and oxygen, were compared. Fuels with DEB are much more efficient in terms of this performance characteristic. The regularities of gasification of solid propellants comprising DEB, a binder, and ammonium perchlorate were studied experimentally. 1,4-Diethynylbenzene containing no oxidizing elements in the molecule can burn by itself due to the high enthalpy of formation (Δ H °_f) in the 2–6 MPa pressure range. The dependences of the combustion rate on the pressure and on binder and ammonium perchlorate contents were elucidated.
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Evaluation of Effectiveness of Solid Fuels Based on High Enthalpy Dispersants for Rocket Ramjet Engines
Russian Journal of Applied Chemistry, 2019Co-Authors: L. S. Yanovskii, D. B. Lempert, V. V. Raznoschikov, I. S. Aver’kovAbstract:The possibility of replacing the currently widely used ammonium perchlorate as an oxidizing agent (dispersant) in the composition of solid boron-containing fuels for aircraft with rocket Ramjet engine was considered by dispersants with reduced nitrogen and oxygen content with a high enthalpy of formation (more than 2 MJ kg^−1) and capable of gasifying solid fuels. The efficiency of fuels with high enthalpy dispersants was evaluated in an optimization setting according to the flight range criterion of the aircraft taking into account the complete combustion of fuel in the afterburner chamber. A number of the most effective dispersants were recommended for further study.
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Thermochemical and Energy Characteristics Di-, Tri-, and Tetra-Azido-Substituted Azines As Gasifying Agents of Solid Fuels for Ramjet Engines
Combustion Explosion and Shock Waves, 2019Co-Authors: D. B. Lempert, S. V. Chapyshev, A. I. Kazakov, N. A. Plishkin, A. V. Shikhovtsev, L. S. YanovskiiAbstract:A number of di-, tri-, and tetraazido-substituted azines as potential energetic dispersing agents of solid propellants for Ramjet Engines have been studied. The enthalpy of combustion and the enthalpy of formation of several azides (2,4,6-triazidopyrimidine, 2,4,6-triazidopyridine, 3,4,5-triazidopyridine-2,6-dicarbonitrile, and 3,4,5,6-tetraazidopyridine-2-carbonitrile) were experimentally determined. Eleven azides were compared with HMX in terms of the enthalpy of combustion in oxygen to CO_2 and water (in the case of the presence of hydrogen in the component), as well as in terms of the temperature of the products of adiabatic conversion of the investigated components due to the high enthalpy of formation in the absence of an external oxidizer and the amount of gases released in this process. The enthalpy of combustion of all the investigated azides burned in air was found to be significantly higher than that of HMX, and for seven of the azides studied, the combustion temperature is significantly higher. As regards the gas release volume (24–31 mol/kg), the azides are inferior to HMX (41.9 mol/kg). Based on the combination of properties, the investigated azides can be considered as promising dispersing agents of solid propellants for Ramjet Engines.
Kaushal Kumar Sharma - One of the best experts on this subject based on the ideXlab platform.
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the recent development of supersonic combustion Ramjet Engines for augmentation of the mixing performance and improvement in combustion efficiency a review
Materials Today: Proceedings, 2021Co-Authors: Kumari Ambe Verma, Sarken Kapayeva, Krishna Murari Pandey, Kaushal Kumar SharmaAbstract:Abstract The present scenario is molded towards the high speed vehicle such as air breathing Engines. There are several combination of Engines are performing well nowadays however to achieve supersonic and above speed with great performance is preliminary obstacles. To excavation into the matter, numerous restrictions are approaching, which has been discussed in detail in this article. The domain that has been selected is based on recent development. The primary focus is to identify the pros and cons of the selected geometry and its behavioral performance. The summary has been drawn by considering supersonic combustion Ramjet engine i.e. scRamjet. Since these type of Engines does not evolve any moving parts to get the desirable thrust at the exit. The present survey summarizes all useful future scope details, which further can be seen impactful into the real world by choosing it.
