Pub Date : 2023-12-01DOI: 10.1134/s0010508223060114
Abstract
A tetrahedral structure model has been proposed to estimate the size of metal agglomerates during combustion of a composite solid propellant. According to this model, oxidizer particles are located at the vertices of a regular tetrahedron and the internal volume of the pyramid is occupied by a mixture of a fuel-binder and metal—the so-called “pocket." Experimental data are compared with the results of calculations using the tetrahedral model, the Cohen model, and the empirical correlations proposed by Hermsen, Salita, Beckstead, Grigoriev, and Duterque. The comparison was made for a composite propellant containing ammonium perchlorate, a binder, and aluminum. It is shown that in some cases the tetrahedral model better predicts the diameter of agglomerates than the other models.
{"title":"Pocket Model with a Tetrahedral Cell for Aluminum Agglomeration in Composite Propellants","authors":"","doi":"10.1134/s0010508223060114","DOIUrl":"https://doi.org/10.1134/s0010508223060114","url":null,"abstract":"<span> <h3>Abstract</h3> <p>A tetrahedral structure model has been proposed to estimate the size of metal agglomerates during combustion of a composite solid propellant. According to this model, oxidizer particles are located at the vertices of a regular tetrahedron and the internal volume of the pyramid is occupied by a mixture of a fuel-binder and metal—the so-called “pocket." Experimental data are compared with the results of calculations using the tetrahedral model, the Cohen model, and the empirical correlations proposed by Hermsen, Salita, Beckstead, Grigoriev, and Duterque. The comparison was made for a composite propellant containing ammonium perchlorate, a binder, and aluminum. It is shown that in some cases the tetrahedral model better predicts the diameter of agglomerates than the other models.</p> </span>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"84 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139556624","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 : 2023-11-21DOI: 10.1134/s0010508223050015
A. V. Pinaev, P. A. Pinaev
Abstract
This paper presents the results of an experimental study of flames propagating with an alternating-sign velocity in methane–air and coal dust–methane–air mixtures in a vertically located closed tube at coal dust concentrations of 0.10–0.42 kg/m3. The results of the study can be useful for developing combustion models and assessing dynamic and thermal effects during combustion of methane–air–coal dust mixtures in coal mines.
{"title":"Flames with Alternating-Sign Velocity in Methane–Air and Methane–Air–Coal Dust Mixtures in a Closed Vertical Tube","authors":"A. V. Pinaev, P. A. Pinaev","doi":"10.1134/s0010508223050015","DOIUrl":"https://doi.org/10.1134/s0010508223050015","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the results of an experimental study of flames propagating with an alternating-sign velocity in methane–air and coal dust–methane–air mixtures in a vertically located closed tube at coal dust concentrations of 0.10–0.42 kg/m<sup>3</sup>. The results of the study can be useful for developing combustion models and assessing dynamic and thermal effects during combustion of methane–air–coal dust mixtures in coal mines.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"119 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523857","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 : 2023-11-21DOI: 10.1134/s0010508223050052
N. A. Kochetov
Abstract
This paper describes synthesis in 5Ti + 3Si + (x)Al((x = 0{-}40)%) activated mixtures and in an 5Ti + 3Si + 10% Al initial mixture. The effect of mechanical activation and aluminum content on burning rate, maximum combustion temperature, morphology, elongation, integrity, and phase composition of combustion products is studied. Mechanical activation expands the limit of Al content to 40% at which samples can burn without preheating. The following intermetallic alloys are synthesized on the basis of Ti–Si–Al: solid solutions based on Ti(Si(_{0.75})Al(_{0.25})_{2 }) titanium silicide and those based on Ti(Al(_{0.9})Si(_{0.1})_{3}) aluminide titanium.
摘要本文介绍了5Ti + 3Si + (x) Al((x = 0{-}40)%) activated mixtures and in an 5Ti + 3Si + 10% Al initial mixture. The effect of mechanical activation and aluminum content on burning rate, maximum combustion temperature, morphology, elongation, integrity, and phase composition of combustion products is studied. Mechanical activation expands the limit of Al content to 40% at which samples can burn without preheating. The following intermetallic alloys are synthesized on the basis of Ti–Si–Al: solid solutions based on Ti(Si(_{0.75})Al(_{0.25})_{2 }) titanium silicide and those based on Ti(Al(_{0.9})Si(_{0.1})_{3}) aluminide titanium.
{"title":"Effect of Aluminum Content and Mechanical Activation on Ti–Si–Al Synthesis","authors":"N. A. Kochetov","doi":"10.1134/s0010508223050052","DOIUrl":"https://doi.org/10.1134/s0010508223050052","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper describes synthesis in 5Ti + 3Si + <span>(x)</span>Al(<span>(x = 0{-}40)</span>%) activated mixtures and in an 5Ti + 3Si + 10% Al initial mixture. The effect of mechanical activation and aluminum content on burning rate, maximum combustion temperature, morphology, elongation, integrity, and phase composition of combustion products is studied. Mechanical activation expands the limit of Al content to 40% at which samples can burn without preheating. The following intermetallic alloys are synthesized on the basis of Ti–Si–Al: solid solutions based on Ti(Si<span>(_{0.75})</span>Al<span>(_{0.25})_{2 })</span> titanium silicide and those based on Ti(Al<span>(_{0.9})</span>Si<span>(_{0.1})_{3})</span> aluminide titanium.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"65 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523836","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 : 2023-11-21DOI: 10.1134/s0010508223050155
G. Luo, L. J. Zhang, J. Q. Fang
Abstract
Experimental and numerical studies of premixed methane–air flame dynamics in an obstructed chamber are carried out. In the experiment, high-speed video photography and pressure transducer measurements are used to study the combustion dynamics. In the numerical simulation, three subgrid-scale viscosity models and three subgrid-scale combustion models are selected to evaluate their individual predictions compared to the experimental data. The high-speed photographs show that the flame propagation process can be divided into four typical stages. When the flame front passes through the obstacle, two distinct vortex structures are formed. The volute flame is the result of the flame–vortex interaction. In addition, the combustion regime experiences a transition from “wrinkled flamelets" to “corrugated flamelets" and finally arrives at a “thin reaction zone regime."
{"title":"Subgrid-Scale Models for Predicting Premixed Methane–Air Flame Propagating in a Chamber with a Rectangular Obstacle","authors":"G. Luo, L. J. Zhang, J. Q. Fang","doi":"10.1134/s0010508223050155","DOIUrl":"https://doi.org/10.1134/s0010508223050155","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Experimental and numerical studies of premixed methane–air flame dynamics in an obstructed chamber are carried out. In the experiment, high-speed video photography and pressure transducer measurements are used to study the combustion dynamics. In the numerical simulation, three subgrid-scale viscosity models and three subgrid-scale combustion models are selected to evaluate their individual predictions compared to the experimental data. The high-speed photographs show that the flame propagation process can be divided into four typical stages. When the flame front passes through the obstacle, two distinct vortex structures are formed. The volute flame is the result of the flame–vortex interaction. In addition, the combustion regime experiences a transition from “wrinkled flamelets\" to “corrugated flamelets\" and finally arrives at a “thin reaction zone regime.\"</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"16 3","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523841","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 : 2023-11-21DOI: 10.1134/s0010508223050131
R. Safari Gh., A. M. Tahsini
Abstract
The purpose of the present study is to investigate the detonation in air containing an (n)-heptane droplet cloud and the effect of the droplet size. A finite volume solver is developed to simulate the two-phase reacting compressible flow using a single-step reaction mechanism. The focus is on the impact of the droplet size on the detonation wave pressure and velocity. For the physical situation considered, the upper limit of the droplet size is determined to ensure self-sustained detonation, and it is shown that medium-size droplets initiate a stronger detonation wave than the gas fuel detonation or than large-size droplets. The distribution of the flow properties behind the wave is analyzed to demonstrate the observed behavior of the droplet size.
{"title":"Droplet Size Impact on n-Heptane Detonation","authors":"R. Safari Gh., A. M. Tahsini","doi":"10.1134/s0010508223050131","DOIUrl":"https://doi.org/10.1134/s0010508223050131","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The purpose of the present study is to investigate the detonation in air containing an <span>(n)</span>-heptane droplet cloud and the effect of the droplet size. A finite volume solver is developed to simulate the two-phase reacting compressible flow using a single-step reaction mechanism. The focus is on the impact of the droplet size on the detonation wave pressure and velocity. For the physical situation considered, the upper limit of the droplet size is determined to ensure self-sustained detonation, and it is shown that medium-size droplets initiate a stronger detonation wave than the gas fuel detonation or than large-size droplets. The distribution of the flow properties behind the wave is analyzed to demonstrate the observed behavior of the droplet size.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"25 7","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523856","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 : 2023-11-21DOI: 10.1134/s0010508223050039
V. A. Arkhipov, A. A. Glazunov, N. N. Zolotorev, E. A. Kozlov, A. G. Korotkikh, V. T. Kuznetsov, V. I. Trushlyakov
Abstract
This paper describes an experimental study of the possibility of combustion of launcher nose cone elements separated and discharged to the Earth’s surface. A new schematic diagram of a honeycomb-free three-layer structure of the nose cone elements burned using a high-energy material charge is proposed. Based on the requirements formulated for the charge characteristics and the analysis of thermodynamic calculations, the base compositions of the high-energy materials are selected. The energy and strength characteristics of the selected HEM compositions are experimentally determined, and their combustion patterns at subatmospheric pressure are determined. It is shown by the laboratory tests on the combustion of the structural elements under consideration with a HEM filler charge that the spent parts of the launcher can be partially utilized.
{"title":"Analyzing the Possibility of Burning the Launcher Nose Cone Elements","authors":"V. A. Arkhipov, A. A. Glazunov, N. N. Zolotorev, E. A. Kozlov, A. G. Korotkikh, V. T. Kuznetsov, V. I. Trushlyakov","doi":"10.1134/s0010508223050039","DOIUrl":"https://doi.org/10.1134/s0010508223050039","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper describes an experimental study of the possibility of combustion of launcher nose cone elements separated and discharged to the Earth’s surface. A new schematic diagram of a honeycomb-free three-layer structure of the nose cone elements burned using a high-energy material charge is proposed. Based on the requirements formulated for the charge characteristics and the analysis of thermodynamic calculations, the base compositions of the high-energy materials are selected. The energy and strength characteristics of the selected HEM compositions are experimentally determined, and their combustion patterns at subatmospheric pressure are determined. It is shown by the laboratory tests on the combustion of the structural elements under consideration with a HEM filler charge that the spent parts of the launcher can be partially utilized.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"64 12","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523865","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 : 2023-11-21DOI: 10.1134/s0010508223050027
S. V. Kostin, P. M. Krishenik
Abstract
Experimental studies of combustion stability to the local excess of the component in a dispersed mixture of titanium and carbon powder are presented. It is shown how the spreading of a melt of a low-melting or liquid reaction product affects the stability of combustion transition through a solid and perforated carbon powder target. The melt motion direction with respect to the front propagation direction is revealed. It is indicated that the stability of the combustion transition through the target is determined by thermal interaction between the combustion wave and the target and is not directly related to the convective heat transfer by the melt.
{"title":"Combustion Stability of Mixtures of Titanium with Soot to the Local Excess of the Component","authors":"S. V. Kostin, P. M. Krishenik","doi":"10.1134/s0010508223050027","DOIUrl":"https://doi.org/10.1134/s0010508223050027","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Experimental studies of combustion stability to the local excess of the component in a dispersed mixture of titanium and carbon powder are presented. It is shown how the spreading of a melt of a low-melting or liquid reaction product affects the stability of combustion transition through a solid and perforated carbon powder target. The melt motion direction with respect to the front propagation direction is revealed. It is indicated that the stability of the combustion transition through the target is determined by thermal interaction between the combustion wave and the target and is not directly related to the convective heat transfer by the melt.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"54 4","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523855","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 : 2023-11-21DOI: 10.1134/s0010508223050143
Q. Jing, D. Wang, C.-L. Shi, Q.-M. Liu, Y. Shen, Z.-S. Wang, C.-Q. Liu, Z. Yang, Z.-L. He, X. Chen, S.-Z. Li, J.-X. Huang
Abstract
The explosion process of the flake aluminum powder–air two-phase flow is experimentally studied in a large-scale long straight horizontal tube with a length of 32.4 m and an inner diameter of 0.199 m. The deflagration-to-detonation transition (DDT) of the aluminum powder–air mixture is analyzed after being ignited by a 40-J electric spark, and the DDT of the mixture at different mass concentrations is compared. The results show that self-sustained detonation can be achieved in the range of 286–532 g/m3 of the flake aluminum powder concentration, and the DDT process of the aluminum powder–air mixture at the concentration of aluminum particles 409 g/m3 (optimal concentration) is analyzed in detail. The detonation velocity and detonation pressure at the optimal concentration are 1690 m/s and 58 bar, respectively. During the self-sustained detonation stage, the detonation overpressure of the multiphase fuel–air mixture exhibits a typical constant oscillation characteristic, while the detonation velocity remains stable. In addition, a double-headed mode helical detonation phenomenon is observed in the detonation wave front of the aluminum powder–air mixture. The structure of the detonation wave, the flow field parameters, and the interaction between the shock wave and the three-wave point trajectory are analyzed. The detonation cell size at the optimal concentration is approximately 486 mm.
{"title":"Deflagration-to-Detonation Characteristics and Detonation Wave Structure of the Flake Aluminum Powder–Air Mixture","authors":"Q. Jing, D. Wang, C.-L. Shi, Q.-M. Liu, Y. Shen, Z.-S. Wang, C.-Q. Liu, Z. Yang, Z.-L. He, X. Chen, S.-Z. Li, J.-X. Huang","doi":"10.1134/s0010508223050143","DOIUrl":"https://doi.org/10.1134/s0010508223050143","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The explosion process of the flake aluminum powder–air two-phase flow is experimentally studied in a large-scale long straight horizontal tube with a length of 32.4 m and an inner diameter of 0.199 m. The deflagration-to-detonation transition (DDT) of the aluminum powder–air mixture is analyzed after being ignited by a 40-J electric spark, and the DDT of the mixture at different mass concentrations is compared. The results show that self-sustained detonation can be achieved in the range of 286–532 g/m<sup>3</sup> of the flake aluminum powder concentration, and the DDT process of the aluminum powder–air mixture at the concentration of aluminum particles 409 g/m<sup>3</sup> (optimal concentration) is analyzed in detail. The detonation velocity and detonation pressure at the optimal concentration are 1690 m/s and 58 bar, respectively. During the self-sustained detonation stage, the detonation overpressure of the multiphase fuel–air mixture exhibits a typical constant oscillation characteristic, while the detonation velocity remains stable. In addition, a double-headed mode helical detonation phenomenon is observed in the detonation wave front of the aluminum powder–air mixture. The structure of the detonation wave, the flow field parameters, and the interaction between the shock wave and the three-wave point trajectory are analyzed. The detonation cell size at the optimal concentration is approximately 486 mm.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"16 2","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523863","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 : 2023-11-21DOI: 10.1134/s0010508223050088
S. A. Bordzilovskii, S. M. Karakhanov, A. V. Plastinin
Abstract
The light emission from samples consisting of a transparent matrix with inclusions of hot spots was studied. The matrix material was water and epoxy resin. Hot spots were generated by shock compression of MS-V hollow glass microballoons. In the pressure range 0.7–29 GPa, a brightness decay time of 280 to 70 ns was recorded. The brightness decay time increased by more than an order of magnitude when replacing the optical window made of solid epoxy resin by LiF. However, even this increased time of brightness decay is much shorter than the estimated times of hot-spot temperature relaxation due to heat conduction in the calculation with stationary parameters ((t_{a} = 10^{- 2}) s) and due to light emission ((tau = 2.4 cdot 10^{-3}) s). It is concluded that the dominant mechanism of temperature relaxation is the turbulent mixing of the medium behind the shock-wave front. The experimental results show that in numerical simulations of the temperature field during shock-wave propagation through a pore, it is necessary to take into account the viscosity and strength of the matrix material.
{"title":"Relaxation of Light Emission from Hot Spots Depending on the Characteristics of the Environment","authors":"S. A. Bordzilovskii, S. M. Karakhanov, A. V. Plastinin","doi":"10.1134/s0010508223050088","DOIUrl":"https://doi.org/10.1134/s0010508223050088","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The light emission from samples consisting of a transparent matrix with inclusions of hot spots was studied. The matrix material was water and epoxy resin. Hot spots were generated by shock compression of MS-V hollow glass microballoons. In the pressure range 0.7–29 GPa, a brightness decay time of 280 to 70 ns was recorded. The brightness decay time increased by more than an order of magnitude when replacing the optical window made of solid epoxy resin by LiF. However, even this increased time of brightness decay is much shorter than the estimated times of hot-spot temperature relaxation due to heat conduction in the calculation with stationary parameters (<span>(t_{a} = 10^{- 2})</span> s) and due to light emission (<span>(tau = 2.4 cdot 10^{-3})</span> s). It is concluded that the dominant mechanism of temperature relaxation is the turbulent mixing of the medium behind the shock-wave front. The experimental results show that in numerical simulations of the temperature field during shock-wave propagation through a pore, it is necessary to take into account the viscosity and strength of the matrix material.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"6 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523840","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 : 2023-11-21DOI: 10.1134/s0010508223050076
A. P. Ershov
Abstract
One of the shortcomings of the classical electromagnetic method of Zavoisky is sensitivity to the non-one-dimensionality of the flow behind the wave front. In this paper, it is proposed to use a four-pin gauge to correct measurements. Two signals are recorded from (Pi)-shaped gauges, one of which is located in a plane tangent to the front, and the other in a plane parallel to the direction of wave propagation. Next, the two signals are combined into a true velocity signal that is insensitive to the curvature of the front. The second difficulty that arises in electromagnetic measurements is the rather large size of the gauges. Typically, the length of the working arm (L) is about 1 cm. An analysis of the potential distribution in the gauge shows that the proposed combined gauge is equivalent to two sensors of zero width, and the effective length (L) is the distance between the midlines of the leads. It is shown that the value of (L) can be reduced to 1.5–2 mm with a lead width of about 0.5 mm. This makes it possible to perform local measurements at spots of millimeter size and use small-size charges. These improvements bring electromagnetic measurements closer to the level of modern optical techniques while using much cheaper equipment.
{"title":"On Electromagnetic Measurements of Particle Velocity","authors":"A. P. Ershov","doi":"10.1134/s0010508223050076","DOIUrl":"https://doi.org/10.1134/s0010508223050076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>One of the shortcomings of the classical electromagnetic method of Zavoisky is sensitivity to the non-one-dimensionality of the flow behind the wave front. In this paper, it is proposed to use a four-pin gauge to correct measurements. Two signals are recorded from <span>(Pi)</span>-shaped gauges, one of which is located in a plane tangent to the front, and the other in a plane parallel to the direction of wave propagation. Next, the two signals are combined into a true velocity signal that is insensitive to the curvature of the front. The second difficulty that arises in electromagnetic measurements is the rather large size of the gauges. Typically, the length of the working arm <span>(L)</span> is about 1 cm. An analysis of the potential distribution in the gauge shows that the proposed combined gauge is equivalent to two sensors of zero width, and the effective length <span>(L)</span> is the distance between the midlines of the leads. It is shown that the value of <span>(L)</span> can be reduced to 1.5–2 mm with a lead width of about 0.5 mm. This makes it possible to perform local measurements at spots of millimeter size and use small-size charges. These improvements bring electromagnetic measurements closer to the level of modern optical techniques while using much cheaper equipment.</p>","PeriodicalId":10509,"journal":{"name":"Combustion, Explosion, and Shock Waves","volume":"36 12","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138523858","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}
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