Pub Date : 2024-04-22DOI: 10.1134/s0010508224010118
O. K. Kamynina, S. G. Vadchenko, I. D. Kovalev, D. V. Prokhorov
Abstract
This paper describes the compounds of refractory metal foils (Ti, Hf, Ta, and Ni) with ceramic layers formed as a result of combustion of reaction tapes rolled from Ti + 0.65C, Ti + 1.7B, and 5Ti + 3Si powder mixtures. Scanning electron microscopy and X-ray diffraction analysis are applied to study the microstructure, elemental composition, and phase composition of multilayer composites obtained by self-propagating high-temperature synthesis. The effect of synthesis conditions (initial temperature and applied pressure) and the initial structure of the samples on various parameters (combustion wave front propagation velocity, microstructure, phase composition, and strength properties) of the resulting layered materials is revealed. It is shown that compounds of metal foils and reaction tapes rolled from powder mixtures during combustion are ensured due to reaction diffusion, mutual impregnation, and chemical reactions occurring in the reaction tapes and on the surface of metal foils. The strength properties of the resulting materials (up to 275 MPa at 25°C and up to 72 MPa at 1100°C) are determined using a three-point loading scheme. The results of this study can contribute to the development of structural materials operating under extreme conditions.
{"title":"Self-Propagating High-Temperature Synthesis of Layered Composite Ti/Hf/Ta/Ni/Ceramics Materials","authors":"O. K. Kamynina, S. G. Vadchenko, I. D. Kovalev, D. V. Prokhorov","doi":"10.1134/s0010508224010118","DOIUrl":"https://doi.org/10.1134/s0010508224010118","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper describes the compounds of refractory metal foils (Ti, Hf, Ta, and Ni) with ceramic layers formed as a result of combustion of reaction tapes rolled from Ti + 0.65C, Ti + 1.7B, and 5Ti + 3Si powder mixtures. Scanning electron microscopy and X-ray diffraction analysis are applied to study the microstructure, elemental composition, and phase composition of multilayer composites obtained by self-propagating high-temperature synthesis. The effect of synthesis conditions (initial temperature and applied pressure) and the initial structure of the samples on various parameters (combustion wave front propagation velocity, microstructure, phase composition, and strength properties) of the resulting layered materials is revealed. It is shown that compounds of metal foils and reaction tapes rolled from powder mixtures during combustion are ensured due to reaction diffusion, mutual impregnation, and chemical reactions occurring in the reaction tapes and on the surface of metal foils. The strength properties of the resulting materials (up to 275 MPa at 25°C and up to 72 MPa at 1100°C) are determined using a three-point loading scheme. The results of this study can contribute to the development of structural materials operating under extreme conditions.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"140 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010106
O. V. Lapshin, O. A. Shkoda
Abstract
The mechanochemical synthesis of titanium nitride during double mechanical activation of titanium powder is studied in argon and in nitrogen gas. The duration of mechanical activation of titanium in argon and nitrogen is varied in experiments. As suggested by the analysis of powder mixture morphology, X-ray diffraction analysis, and microanalysis, the preliminary mechanical activation of titanium in argon contributes to accelerating the mechanochemical synthesis of titanium nitride. Analytical relationships are obtained and theoretical estimates are given that make it possible to predict the process of double mechanical activation of titanium.
{"title":"Titanium Nitride Synthesis during Double Mechanical Activation of Titanium—in Argon and in Nitrogen","authors":"O. V. Lapshin, O. A. Shkoda","doi":"10.1134/s0010508224010106","DOIUrl":"https://doi.org/10.1134/s0010508224010106","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The mechanochemical synthesis of titanium nitride during double mechanical activation of titanium powder is studied in argon and in nitrogen gas. The duration of mechanical activation of titanium in argon and nitrogen is varied in experiments. As suggested by the analysis of powder mixture morphology, X-ray diffraction analysis, and microanalysis, the preliminary mechanical activation of titanium in argon contributes to accelerating the mechanochemical synthesis of titanium nitride. Analytical relationships are obtained and theoretical estimates are given that make it possible to predict the process of double mechanical activation of titanium.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"99 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s001050822401009x
K. A. Bolgaru, A. A. Reger
Abstract
The possibility of obtaining a composite material from a ferroalloy based on silicon, aluminum, and zirconium nitrides using self-propagating high-temperature synthesis is considered. It is shown that introducing up to 35% of a nitrogen-containing additive on the basis of ferroalumosilicozirconium to the initial ferroalloy leads to an increase in the nitrogen fraction, emission of the basic nitride phases in combustion products, deceleration of the combustion wave front, and reduction of the maximum combustion temperature. It is revealed that adding more than 20% of a preliminary nitrided material makes it possible to stabilize the combustion wave front propagation conditions and to obtain combustion products with a macroscopically homogeneous composition. Under the conditions of natural filtration of nitrogen, combustion of a powder mixture based on ferroalumosilicozirconium and a nitrided material yields a composite consisting of AlN, Si3N4, ZrN, and (alpha)-Fe phases.
{"title":"Synthesis of a Nitrided Composite Material from Ferroalumosilicozirconium during Combustion","authors":"K. A. Bolgaru, A. A. Reger","doi":"10.1134/s001050822401009x","DOIUrl":"https://doi.org/10.1134/s001050822401009x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The possibility of obtaining a composite material from a ferroalloy based on silicon, aluminum, and zirconium nitrides using self-propagating high-temperature synthesis is considered. It is shown that introducing up to 35% of a nitrogen-containing additive on the basis of ferroalumosilicozirconium to the initial ferroalloy leads to an increase in the nitrogen fraction, emission of the basic nitride phases in combustion products, deceleration of the combustion wave front, and reduction of the maximum combustion temperature. It is revealed that adding more than 20% of a preliminary nitrided material makes it possible to stabilize the combustion wave front propagation conditions and to obtain combustion products with a macroscopically homogeneous composition. Under the conditions of natural filtration of nitrogen, combustion of a powder mixture based on ferroalumosilicozirconium and a nitrided material yields a composite consisting of AlN, Si<sub>3</sub>N<sub>4</sub>, ZrN, and <span>(alpha)</span>-Fe phases.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"81 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010015
B. F. Boyarshinov, S. Yu. Fedorov, R. Kh. Abdrakhmanov, V. S. Naumkin
Abstract
The initial part of a hydrogen jet exhausting upward from a (2 times 20) mm slot and burning in air is studied. The profiles of the streamwise and transverse velocity are determined by means of particle image velocimetry; the local temperature distribution and the composition of stable substances are obtained by the Raman scattering method with the use of a focusing resonator system. Based on experimental data, the contributions of molecular and convective transfer mechanisms to the heat release intensity is determined. It is shown that the maximum intensity of heat release depends mainly on gas-dynamic and thermophysical characteristics of the gas flow during its macroscopic motion.
{"title":"Experimental Study of the Flame Structure and Heat and Mass Transfer in a Hydrogen Jet Exhausting from a Slot into Air","authors":"B. F. Boyarshinov, S. Yu. Fedorov, R. Kh. Abdrakhmanov, V. S. Naumkin","doi":"10.1134/s0010508224010015","DOIUrl":"https://doi.org/10.1134/s0010508224010015","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The initial part of a hydrogen jet exhausting upward from a <span>(2 times 20)</span> mm slot and burning in air is studied. The profiles of the streamwise and transverse velocity are determined by means of particle image velocimetry; the local temperature distribution and the composition of stable substances are obtained by the Raman scattering method with the use of a focusing resonator system. Based on experimental data, the contributions of molecular and convective transfer mechanisms to the heat release intensity is determined. It is shown that the maximum intensity of heat release depends mainly on gas-dynamic and thermophysical characteristics of the gas flow during its macroscopic motion.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"7 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140637253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010155
A. B. Medvedev
Abstract
Model expressions are obtained for the concentration diffusion coefficient and thermal diffusion factor of a binary mixture obeying the Van der Waals equation of state. Model calculations at elevated pressure (density) require the equation of state parameters and thermal diffusion factor of the mixture in a low-density ideal gas state. The behavior of the model relations is studied as a function of pressure along isotherms. Near the critical state, the model diffusion coefficient has a minimum and the thermal diffusion coefficient has a maximum. The diffusion and thermal diffusion models at elevated pressure are compared with experimental data for a number of mixtures. It is shown that they are in qualitative and generally quantitative agreement at different temperatures and component concentrations. The Van der Waals equation is not quite suitable for describing experimental data on compressibility and phase equilibrium at high pressure. This requires more complex and flexible modifications of the equation. Generalized expressions are given for model diffusion characteristics of the binary mixture in the case of such equations of state.
{"title":"Diffusion and Thermal Diffusion Coefficients of a Binary Mixture in the Van der Waals Model","authors":"A. B. Medvedev","doi":"10.1134/s0010508224010155","DOIUrl":"https://doi.org/10.1134/s0010508224010155","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Model expressions are obtained for the concentration diffusion coefficient and thermal diffusion factor of a binary mixture obeying the Van der Waals equation of state. Model calculations at elevated pressure (density) require the equation of state parameters and thermal diffusion factor of the mixture in a low-density ideal gas state. The behavior of the model relations is studied as a function of pressure along isotherms. Near the critical state, the model diffusion coefficient has a minimum and the thermal diffusion coefficient has a maximum. The diffusion and thermal diffusion models at elevated pressure are compared with experimental data for a number of mixtures. It is shown that they are in qualitative and generally quantitative agreement at different temperatures and component concentrations. The Van der Waals equation is not quite suitable for describing experimental data on compressibility and phase equilibrium at high pressure. This requires more complex and flexible modifications of the equation. Generalized expressions are given for model diffusion characteristics of the binary mixture in the case of such equations of state.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"115 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140637119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010040
A. G. Shmakov, A. A. Paletsky, O. V. Netskina, K. A. Dmitruk, O. V. Komova, S. A. Mukha
Abstract
Organometallic complexes of transition metals with inorganic anions are considered as promising precursors for the synthesis of nanoscale materials used in various applications including chemical catalysis. In this work, organometallic complexes of nickel, iron, and copper with imidazole as an organic ligand and the nitrate anion as an inorganic ligand were synthesized and characterized. The kinetic parameters of thermal decomposition of the synthesized organometallic complexes were determined by low heating-rate thermogravimetric analysis and high-speed dynamic mass spectrometric thermal analysis. The main gaseous products of thermal decomposition of the complexes under high-speed heating were identified. The chemical and phase compositions of condensed combustion products of the organometallic complexes in air were studied.
{"title":"Kinetics and Composition of Gaseous Products of Pyrolysis of Organometallic Complexes of Nickel, Iron, and Copper with Inorganic Anions","authors":"A. G. Shmakov, A. A. Paletsky, O. V. Netskina, K. A. Dmitruk, O. V. Komova, S. A. Mukha","doi":"10.1134/s0010508224010040","DOIUrl":"https://doi.org/10.1134/s0010508224010040","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Organometallic complexes of transition metals with inorganic anions are considered as promising precursors for the synthesis of nanoscale materials used in various applications including chemical catalysis. In this work, organometallic complexes of nickel, iron, and copper with imidazole as an organic ligand and the nitrate anion as an inorganic ligand were synthesized and characterized. The kinetic parameters of thermal decomposition of the synthesized organometallic complexes were determined by low heating-rate thermogravimetric analysis and high-speed dynamic mass spectrometric thermal analysis. The main gaseous products of thermal decomposition of the complexes under high-speed heating were identified. The chemical and phase compositions of condensed combustion products of the organometallic complexes in air were studied.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"5 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010088
O. G. Kryukova, A. A. Nevmyvaka, A. A. Akulinkin, T. V. Tatarinova
Abstract
Targeted synthesis of oxynitride composites is implemented by means of organizing coupled processes. Interaction of ferrosilicon with nitrogen during combustion is considered as the main (inducing) process. The phase composition of the products of the coupled processes is determined by the chemical and phase compositions of the components added to ferrosilicon before performing self-propagating high-temperature synthesis. The influence of the basic products of the synthesis on the burning rate, fraction of nitrogen, phase composition, and morphology of synthesis products is considered. Chemical stages of ferrosilicon interaction with additives of natural minerals (zircon, ilmenite, and shungite) and aluminum in a nitrogen medium are demonstrated. The phase composition is determined by chemical transformations in a combustion wave. It is found that addition of aluminum leads to reduction or elimination of the Si2N2O phase in synthesis products with an increase in the aluminum fraction and obtaining composites based on the Si3N4 (SiAlON) solid solution. The microstructure of combustion products is presented by aggregates (5–10 (mu)m) composed of small faceted crystals, shapeless structures, and crystal flakes. Oxynitride composites with an open porosity value of 51.0–68.8% are obtained.
{"title":"Synthesis of Oxynitride Composites during Combustion of a Ferrosilicon–Natural Mineral–Aluminum Mixture in Nitrogen","authors":"O. G. Kryukova, A. A. Nevmyvaka, A. A. Akulinkin, T. V. Tatarinova","doi":"10.1134/s0010508224010088","DOIUrl":"https://doi.org/10.1134/s0010508224010088","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Targeted synthesis of oxynitride composites is implemented by means of organizing coupled processes. Interaction of ferrosilicon with nitrogen during combustion is considered as the main (inducing) process. The phase composition of the products of the coupled processes is determined by the chemical and phase compositions of the components added to ferrosilicon before performing self-propagating high-temperature synthesis. The influence of the basic products of the synthesis on the burning rate, fraction of nitrogen, phase composition, and morphology of synthesis products is considered. Chemical stages of ferrosilicon interaction with additives of natural minerals (zircon, ilmenite, and shungite) and aluminum in a nitrogen medium are demonstrated. The phase composition is determined by chemical transformations in a combustion wave. It is found that addition of aluminum leads to reduction or elimination of the Si<sub>2</sub>N<sub>2</sub>O phase in synthesis products with an increase in the aluminum fraction and obtaining composites based on the Si<sub>3</sub>N<sub>4</sub> (SiAlON) solid solution. The microstructure of combustion products is presented by aggregates (5–10 <span>(mu)</span>m) composed of small faceted crystals, shapeless structures, and crystal flakes. Oxynitride composites with an open porosity value of 51.0–68.8% are obtained.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"140 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010076
A. N. Avramchik, B. Sh. Braverman
Abstract
This paper presents the results of thermodynamic calculation of adiabatic temperature and the equilibrium composition of products of HfO2 reduction with calcium depending on carbon and calcium content at different pressures. The formation of solid HfN–HfC solutions is identified with the formation of hafnium carbonitride. It is shown that adiabatic temperatures lie in a range of 2000–2900 K, and its elevation is limited by the melting of CaO at 2900 K. The introduction of carbon often reduces the adiabatic temperature, and a pressure rise leads to its increase. A connection is revealed between the composition of products and the type of temperature curves. The main reason why adiabatic temperature rises along with pressure is a displacement of equilibrium toward the formation of condensed phases and an increase in the fraction of HfN in the products.
摘要 本文介绍了绝热温度的热力学计算结果，以及不同压力下碳和钙含量对二氧化铪与钙还原产物平衡组成的影响。固体 HfN-HfC 溶液的形成与碳氮化铪的形成相一致。研究表明，绝热温度在 2000-2900 K 范围内，绝热温度的升高受到 2900 K CaO 熔化的限制。产品成分与温度曲线类型之间存在联系。绝热温度随压力升高而升高的主要原因是平衡向凝聚相的形成移动，以及产品中 HfN 分数的增加。
{"title":"Equilibrium Composition of Products in a Hafnium Dioxide–Calcium–Nitrogen–Carbon Mixture at Adiabatic Combustion Temperature","authors":"A. N. Avramchik, B. Sh. Braverman","doi":"10.1134/s0010508224010076","DOIUrl":"https://doi.org/10.1134/s0010508224010076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the results of thermodynamic calculation of adiabatic temperature and the equilibrium composition of products of HfO<sub>2</sub> reduction with calcium depending on carbon and calcium content at different pressures. The formation of solid HfN–HfC solutions is identified with the formation of hafnium carbonitride. It is shown that adiabatic temperatures lie in a range of 2000–2900 K, and its elevation is limited by the melting of CaO at 2900 K. The introduction of carbon often reduces the adiabatic temperature, and a pressure rise leads to its increase. A connection is revealed between the composition of products and the type of temperature curves. The main reason why adiabatic temperature rises along with pressure is a displacement of equilibrium toward the formation of condensed phases and an increase in the fraction of HfN in the products.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"6 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010039
I. A. Bedarev, A. A. Syrovaten, V. M. Temerbekov
Abstract
A mathematical method is developed for solving the problem of detonation initiation in a hydrogen–air mixture by a small-diameter sphere flying with a velocity greater than the Chapman–Jouguet detonation velocity. The mathematical model verification is performed against experimental data on the detonation cell size in hydrogen–oxygen and hydrogen–air mixtures. Depending on the pressure in the mixture, which is varied from 100 to 250 kPa, three types of oblique detonation waves are obtained: (1) stabilized oblique detonation wave at 250 kPa; (2) stabilized oblique detonation wave of the “straw hat" type at 200 kPa; (3) periodic regime with an attenuated oblique detonation wave, which was not observed in previous experiments, at 125 kPa. At 100 kPa, a regime of shock-initiated combustion is observed. Based on an analytical dependence, the energy of detonation initiation by a high-velocity projectile is estimated, and the analytical and numerical data are found to be in good agreement.
{"title":"Numerical Simulation of Oblique Detonation Initiation by a High-Velocity Projectile Flying in a Hydrogen–Air Mixture","authors":"I. A. Bedarev, A. A. Syrovaten, V. M. Temerbekov","doi":"10.1134/s0010508224010039","DOIUrl":"https://doi.org/10.1134/s0010508224010039","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A mathematical method is developed for solving the problem of detonation initiation in a hydrogen–air mixture by a small-diameter sphere flying with a velocity greater than the Chapman–Jouguet detonation velocity. The mathematical model verification is performed against experimental data on the detonation cell size in hydrogen–oxygen and hydrogen–air mixtures. Depending on the pressure in the mixture, which is varied from 100 to 250 kPa, three types of oblique detonation waves are obtained: (1) stabilized oblique detonation wave at 250 kPa; (2) stabilized oblique detonation wave of the “straw hat\" type at 200 kPa; (3) periodic regime with an attenuated oblique detonation wave, which was not observed in previous experiments, at 125 kPa. At 100 kPa, a regime of shock-initiated combustion is observed. Based on an analytical dependence, the energy of detonation initiation by a high-velocity projectile is estimated, and the analytical and numerical data are found to be in good agreement.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"16 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1134/s0010508224010131
J. Liu, D. Wang, Zh. Zhang, F. Li
Abstract
Boron is one of the most valuable fuels for rocket propellants. However, the boron oxide (B2O3) on the B surface has a high boiling point (1860°C), which hinders the contact between the internal active B and the oxidation component during the ignition and combustion process. As a result, the ignition energy of B is higher and the combustion reaction rate is lower. In order to improve the ignition performance and reaction rate of B, a surface modification of B by means of surface purification by a solvent, surface grafting, and making a composite with aluminum (Al), which has a high combustion temperature, has been prepared. Composite particles of B purified by ethanol and thick flake Al (TF-Al), denoted by EB/TF-Al, have the fastest reaction rate higher by 96.6% than that of raw B and TF-Al composite particles (RB/TF-Al). Surface grafting of B with TF-Al composite particles (KHB-3/TF-Al) ensure the minimum ignition energy, which is 29.1% lower than that of raw B. As the ignition performance and reaction rate of B are improved by means of surface modification, the performance of B-based rocket propellants is expected to be improved.
摘要 硼是火箭推进剂中最有价值的燃料之一。然而，硼表面的氧化硼（B2O3）沸点较高（1860°C），在点火和燃烧过程中阻碍了内部活性硼与氧化组分的接触。因此，B 的点火能量较高，燃烧反应速率较低。为了提高 B 的点火性能和反应速率，制备了一种通过溶剂表面净化、表面接枝以及与燃烧温度较高的铝（Al）复合等手段对 B 进行表面改性的方法。经乙醇提纯的 B 与厚片铝（TF-Al）的复合颗粒（EB/TF-Al）的反应速率最快，比原始 B 与 TF-Al 复合颗粒（RB/TF-Al）的反应速率高 96.6%。通过表面改性提高 B 的点火性能和反应速率，有望改善 B 基火箭推进剂的性能。
{"title":"Improvement of the Ignition Performance and Reaction Rate of Boron by Surface Modification","authors":"J. Liu, D. Wang, Zh. Zhang, F. Li","doi":"10.1134/s0010508224010131","DOIUrl":"https://doi.org/10.1134/s0010508224010131","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Boron is one of the most valuable fuels for rocket propellants. However, the boron oxide (B<sub>2</sub>O<sub>3</sub>) on the B surface has a high boiling point (1860°C), which hinders the contact between the internal active B and the oxidation component during the ignition and combustion process. As a result, the ignition energy of B is higher and the combustion reaction rate is lower. In order to improve the ignition performance and reaction rate of B, a surface modification of B by means of surface purification by a solvent, surface grafting, and making a composite with aluminum (Al), which has a high combustion temperature, has been prepared. Composite particles of B purified by ethanol and thick flake Al (TF-Al), denoted by EB/TF-Al, have the fastest reaction rate higher by 96.6% than that of raw B and TF-Al composite particles (RB/TF-Al). Surface grafting of B with TF-Al composite particles (KHB-3/TF-Al) ensure the minimum ignition energy, which is 29.1% lower than that of raw B. As the ignition performance and reaction rate of B are improved by means of surface modification, the performance of B-based rocket propellants is expected to be improved.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"40 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号