Molecular turbulent evaporation in a gravitational field

Дильман, В. В.; Lotkhov, V. A.

doi:10.1134/s0040579515010017

Cited by 13 publications

(9 citation statements)

References 6 publications

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“…In experiments on the study of mixing in multicomponent systems at different pressures and compositions , and diffusion of a mixture of solution vapors into an inert gas , , convective flows were observed leading to a synergistic effect associated with a significant increase in the rate of mixing of the system components. At the same time , the predominant transfer of the component with the highest molecular weight was noted, which is not typical for diffusion.…”

Section: Introductionmentioning

confidence: 99%

Features of Multicomponent Mass Transfer in Gas Mixtures Containing Hydrocarbon Components

2019

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The features characterizing the transition from a diffusion process to the concentration gravitational convection in multicomponent gas mixtures containing hydrocarbon components are analyzed. It is demonstrated that this transition is possible due to the difference in interdiffusion coefficients of components, initial concentration of components, and the pressure of the experiment. A mathematical model for describing the transition from the diffusion process to the concentration gravitational convection in multicomponent gas mixtures is considered. The key feature indicating the transfer from the diffusion regime to the convective one is the curvature of an isoline of the heavy component of the gas mixture.

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Section: Introductionmentioning

confidence: 99%

Features of Multicomponent Mass Transfer in Gas Mixtures Containing Hydrocarbon Components

2019

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“…Experimental studies of multicomponent mixing in gas mixtures with significant difference in diffusion coefficients have shown that, under certain conditions, convective instability may occur in them, followed by appearance of structured flows [10,11]. Further experimental [12][13][14] and computational-theoretical [15][16][17] studies have shown variety of thermophysical concentration flows at the boundary of "diffusion-convection" regime change. Feature of registered flows is that occur in gas systems under condition of decrease in the density of mixture with height, which is not typical for diffusion.…”

Section: Optical Experimental Visualization Of Convective Flows Durin...mentioning

confidence: 99%

Comparative study of evolution of structured flows at boundary of the regime change “diffusion — concentration convection” in isothermal multicomponent mixing in gases by techniques of visual and numerical analysis

Kossov¹,

Krasikov²,

Zhaneli³

et al. 2023

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During isothermal multicomponent diffusion process, the number of effects appear that are not observed visually when mixed in binary mixtures. These include occurrence of convective instability with subsequent formation of structured flows. The feature of this type of mixing is that convection is realized under conditions of decrease in density of mixture with height. Flow visualization method allows to fix information about distribution of medium parameters by dynamics of structures in convective flows. Application of computer processing methods, as well as techniques of identifying images of thermophysical fields, allows to obtain quantitative information about convective flows. For an isothermal ternary gas mixture heliumargonnitrogen, shadow images of structural formations formed in convective flows due to the instability of mechanical equilibrium are represented in this work. To carry out digital analysis of experimental shadow images, a simplified virtual model of the lower chamber of the diffusion cell was created. Based on digital analysis of visual images, quantitative characteristics related to estimation of the size of convective formations, period of their formation, and linear velocity of convection cells when moving through diffusion channel are presented. It has been established that the growing convective disturbances arising in the system cause a change in the characteristic scale of convective cells. The analysis of shadow images also showed that a vortex is formed in convective flows, which consists mainly of a component with the highest molecular weight. Comparison of visual images of experimental fields with simulation flows is implemented, on the basis of which composition of mixture components in convective structures is estimated. It is shown that the obtained value of the concentration of the heavy component in the vortex filament can be taken as the minimum.

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“…A feature of experimental studies [16,17] was that concentration gravitational convection was implemented in systems with an initial stable stratification of the mixture density. Further study of the change in the "diffusion-concentration gravitational convection" regimes showed that the emergence and the development of convective regimes significantly depends on the ratios between the diffusion coefficients of the components, the pressure and the initial composition of the mixtures studied [18][19][20][21], and the geometric characteristics of the cavities and the properties of the medium [22], whose influence was analyzed in the similar problems of the heat-gravitational convection [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…The specificity of the results presented in [16][17][18][19][20][21][22] consists in the study of transition states caused by the multicomponent diffusion. However, it is difficult to estimate the influence of diffusion mechanisms on the convective component of the emerging near-boundary currents, since the multicomponent diffusion transfer is determined by the simultaneous action of several concentration gradients.…”

Section: Introductionmentioning

confidence: 99%

Convective mass transfer of a binary gas mixture in an inclined channel

et al. 2022

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The influence of a slope angle on the stability of mechanical equilibrium in binary gaseous mixtures has been investigated both experimentally and numerically. Experimental studies have shown that the angle of inclination of the channel relative to the horizontal plane can be critical in convective mixing. When this angle is reached, the system performs a kinetic transition from an unstable to a stable state, that is, to diffusion. The problem is solved by the Lattice Boltzmann method using the two-dimensional Navier-Stokes equation, the continuity equation and the equation of concentration. Calculations are performed to study binary mixtures with different angles of inclination of the diffusion channel with respect to the vertical axis. Due to the increase of the angle of inclination, the convective flow intensity decreases. Numerical data on the structure fields of concentrations at different times depending on the increase of the slope angle are obtained.

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Molecular turbulent evaporation in a gravitational field

Cited by 13 publications

References 6 publications

Features of Multicomponent Mass Transfer in Gas Mixtures Containing Hydrocarbon Components

Features of Multicomponent Mass Transfer in Gas Mixtures Containing Hydrocarbon Components

Comparative study of evolution of structured flows at boundary of the regime change “diffusion — concentration convection” in isothermal multicomponent mixing in gases by techniques of visual and numerical analysis

Convective mass transfer of a binary gas mixture in an inclined channel

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