Fluid Dynamics最新文献

Direct Statistical Simulation of Radiation behind the Shock Wave Front in a CO2 and N2 Mixture

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S001546282460425X

A. L. Kusov, N. G. Bykova, G. Ya. Gerasimov, I. E. Zabelinskii, P. V. Kozlov, V. Yu. Levashov

引用次数: 0

Evaluation of the Influence of Secondary Processes on the Results of the Measurement of Rate Constants of Gas-Phase Chemical Reactions

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604364

M. F. Danilov

{"title":"Evaluation of the Influence of Secondary Processes on the Results of the Measurement of Rate Constants of Gas-Phase Chemical Reactions","authors":"M. F. Danilov","doi":"10.1134/S0015462824604364","DOIUrl":"10.1134/S0015462824604364","url":null,"abstract":"Using the example of one of the important chemical reactions OH + O → O2 + H in the mechanism of combustion of a mixture of hydrogen and oxygen, current issues of constructing a model for measuring rate constants are considered, and the role of secondary chemical reactions in this process is analyzed. It is noted that to assess the adequacy of the kinetic model of the measurement process, the intended purpose of the model is important; the difference in requirements for models designed to solve direct and inverse kinetic problems is emphasized. The analysis is focused on one of the components of the uncertainty in the results of measurements of rate constants of chemical reactions, which is due to the systematic effect associated with incomplete consideration of secondary reactions in constructing a kinetic model of the measuring process. In considering this issue, it is proposed to use the principle of necessary and sufficient redundancy, when the relative contributions of reactions are not assessed a priori based on a limited number of leading processes, but are calculated automatically taking into account the entire set of reactions from the basic set. Mathematical modeling was used to numerically analyze the experimental results; the most important secondary processes are identified that can play a significant role in determining the reaction constant. The systematic components of the uncertainty of the measurement results are examined; corrections are proposed to compensate for them, and refined values of the constants at a temperature of T = 295 K are presented.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"59 5","pages":"1511 - 1528"},"PeriodicalIF":1.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107856","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}

引用次数: 0

Formation of a Floating-Up Vortex during the Merging of an Ethanol Droplet with Water in the Intrusive Mode

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604200

B. Djoudar, Yu. D. Chashechkin, A. Yu. Ilinykh

{"title":"Formation of a Floating-Up Vortex during the Merging of an Ethanol Droplet with Water in the Intrusive Mode","authors":"B. Djoudar, Yu. D. Chashechkin, A. Yu. Ilinykh","doi":"10.1134/S0015462824604200","DOIUrl":"10.1134/S0015462824604200","url":null,"abstract":"The evolution of the pattern of a drop of a 95% ethanol aqueous solution dyed brilliant green merging with water is traced using a high-speed video recording. In the traditional sequence of flows recorded in the intrusive mode, including the inflow of a drop into the liquid bulk with the formation of a lenticular intrusion, the delayed formation, development, collapse of the cavity, and the transformation of the intrusion into a plunging ring vortex, a new type of vortex ring is observed in the pattern of the merger of a drop of a lighter liquid being mixed. When the cavity maximal depth is reached, a compact volume containing drop matter is separated from the center of the pointed bottom of the cavity into the liquid bulk. The gradually submerging volume transforms into a small annular vortex, which, having reached its maximum depth, stops and forms a compact secondary intrusion of a cylindrical shape. Next, the intrusion, in which the lighter liquid of the drop is partially preserved, begins to float up and gradually transforms into a new ring vortex. The rising vortex leaves a cylindrical trace in the target liquid with a shell colored by the drop pigment. The diameter of the vortex gradually increases, and the trace takes on a bottle-shaped shape.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"59 5","pages":"1529 - 1539"},"PeriodicalIF":1.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108005","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}

引用次数: 0

Fine Structure of Substance Distribution of a Compound Drop in the Target Fluid in the Splash Formation Mode

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604194

Yu. D. Chashechkin, A. Yu. Ilinykh, S. K. Khaiirbekov

{"title":"Fine Structure of Substance Distribution of a Compound Drop in the Target Fluid in the Splash Formation Mode","authors":"Yu. D. Chashechkin, A. Yu. Ilinykh, S. K. Khaiirbekov","doi":"10.1134/S0015462824604194","DOIUrl":"10.1134/S0015462824604194","url":null,"abstract":"The evolution of the regular fine structure of the colored substance distribution pattern during the spreading of a freely falling compound drop in deep water is traced for the first time using technical photo and video recording methods. The flow pattern is studied at the initial stage of the formation of the cavity and crown during the merger of a compound drop, whose core, a drop of alizarin ink solution, is covered with an oil shell. Banded structures are observed in the distribution of the colored liquid at the bottom of the cavern and the walls of the crown. The formation of banded elements of the flow pattern is associated with the influence of the processes of conversion of the available potential surface energy (APSE) during the destruction of the contact surfaces of the merging liquids. The position of the nucleus in the drop is not controlled and is determined by the formation conditions. The breakdown of the ink core into fibers is observed in all experiments in this series. The area of coverage of the surface of the cavity and the crown with the colored liquid reach a maximum at the central position of the core.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"59 5","pages":"1500 - 1510"},"PeriodicalIF":1.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107931","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}

引用次数: 0

Experimental and Numerical Modeling of Supersonic Jets Expanding into a Rarefied Medium Part 1: Noncondensing Flows

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604340

A. E. Zarvin, K. A. Dubrovin, L. V. Yarkov, Ye. A. Bondar, A. V. Zaitsev, V. V. Kalyada, A. S. Yaskin

{"title":"Experimental and Numerical Modeling of Supersonic Jets Expanding into a Rarefied Medium Part 1: Noncondensing Flows","authors":"A. E. Zarvin, K. A. Dubrovin, L. V. Yarkov, Ye. A. Bondar, A. V. Zaitsev, V. V. Kalyada, A. S. Yaskin","doi":"10.1134/S0015462824604340","DOIUrl":"10.1134/S0015462824604340","url":null,"abstract":"This paper is the first part of a study aimed at developing methods for the experimental and numerical modeling of jet flows with significant rarefaction effects. The experimental measurements of flow parameters in jets expanding into a vacuum or highly rarefied medium are carried out on the modern gas-dynamic complex LEMPUS-2. The electron beam diagnostic (EBD) method was used for dimensional visualization of the flows and measurements of the absolute values of the local flow density. For the numerical simulation of a stationary axisymmetric nitrogen jet expanding from a sonic nozzle into a rarefied medium, a hybrid approach is employed: gas parameters in the dense flow region are determined using the solution of the Navier–Stokes equations, and in the rarefied flow region, using direct simulation Monte Carlo. The experimental and numerical methods are compared for this problem under conditions of no condensation. The results of the numerical calculations and experiments are compared with each other and with the published theoretical data. The close agreement of the results confirms the strong predictive ability of the methods used for the outflow of a noncondensable gas from sonic nozzles into a rarefied medium.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"59 5","pages":"1677 - 1690"},"PeriodicalIF":1.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108006","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}

引用次数: 0

Multiscale Simulation of Gas-Particle Flows in the Combustion Chambers of Solid-Propellant Rocket Motors

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S001546282460411X

N. Brykov, K. Volkov, V. Emelyanov, A. Efremov

{"title":"Multiscale Simulation of Gas-Particle Flows in the Combustion Chambers of Solid-Propellant Rocket Motors","authors":"N. Brykov, K. Volkov, V. Emelyanov, A. Efremov","doi":"10.1134/S001546282460411X","DOIUrl":"10.1134/S001546282460411X","url":null,"abstract":"The development and application of numerical simulation to the study of gas-dynamic processes occurring in solid-propellant rocket motors (SPRMs) is discussed. A characteristic feature of internal flows in the SPRM channels and nozzles is the presence of the condensed phase of nonspherical particles. Mathematical problems in this area feature the simultaneous occurrence of processes on many time and spatial scales, which describe the formation of agglomerate particles, their combustion, and transport in a flow of combustion products in internal channels and nozzles. A multilevel multiscale technique that combines models describing the state of the system at the micro-, meso-, and macroscales is the approach used to solve these problems. An overview of models varying in complexity and level of detail is given. The construction of multiscale models is considered in relation to the simulation of two-phase flows with metal-oxide agglomerates formed in the propellant channel and representing drops of molten metal with oxide particles attached to their surface. The options of the developed approach are demonstrated by the calculations of flows of combustion products containing agglomerate particles in the channels and nozzles of propulsion systems.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"59 5","pages":"1416 - 1436"},"PeriodicalIF":1.0,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107770","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}

引用次数: 0

Heat Transfer and Behavior of Silicon Carbide Samples in Subsonic Air, Nitrogen, and Carbon Dioxide Plasma Flows

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604133

A. V. Chaplygin, S. S. Galkin, I. V. Lukomskii, E. S. Tepteeva, S. A. Vasil’evskii, A. F. Kolesnikov, E. P. Simonenko, N. P. Simonenko

引用次数: 0

On the Uncertainty of Modeling the Interaction of a Meteoroid with the Atmosphere at Various Entry Angles

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-02-02 DOI: 10.1134/S0015462824604236

I. G. Brykina, L. A. Egorova

引用次数: 0

Numerical Modeling of Flow and Heat Transfer in a Flat Confuser