IRN AP09259248 «Arising of concentration gravitational convection in multicomponent diffusion in stably stratified medium».

AP09259248 «Arising of concentration gravitational convection in multicomponent diffusion in stably stratified medium».

Relevance of the project. Relevance of proposed project is high. Modern technologies for the production of materials, the extraction of hydrocarbon raw materials, and the prediction of natural phenomena require an adequate description of the processes of heat and mass transfer in liquids and gases, which, as a rule, mixtures of various substances with a large number of components. Difficulties in describing multicomponent mixtures are determined by the presence of several mechanisms of heat and mass transfer (convection, thermal conductivity, diffusion, thermal diffusion, diffusive thermal conductivity), and for systems consisting of three or more components, it is necessary to take into account cross-diffusion effects. To control the behavior of such systems, new knowledge of the features of combined mass transfer is needed both in the diffusion and convective stages of multicomponent mixing, as well as at the boundary of the “diffusion – concentration gravitational convection” regime change.

Principal distinguishing feature of the research from existing analogues is: obtaining new experimental and calculated data on determining the stability boundaries for three – and four-component gas mixtures containing components with different thermophysical properties; researching supercritical flows at the initial stage of their formation; verifying the results of numerical studies with experimental data, which obtained by various methods in laboratory conditions.

Works provided for by the project relate to fundamental research, as a result of which fundamentally new and world-class results will be obtained in the field of stability and nonlinear dynamics of multicomponent hydrodynamic systems, new methods for controlling their behavior will be developed. Results of the research on multicomponent transfer can be used in technologies to reduce the environmental load on the environment, for example, in separation technologies, which corresponds to the national priorities of socio-economic development of the Kazakhstan.

Following main approaches to conducting research are used in the work to achieve the set goals and justifications:

Scientific research approaches, which applied in this project based on the fundamental laws of physical kinetics and hydrodynamics of multicomponent heat and mass transfer. Experimental approaches are based on the application of the two-column method and the diffusion bridge method. Observations of stationary, quasi-stationary and non-stationary processes of multicomponent diffusion and convective mixing in experimental stands, which implementing these methods will allow to study the special regimes and properties of the studied gas mixtures. As a result, a spectrum of experimental data will be obtained, that characterizes main features of combined mass transfer.

Computational-theoretical and numerical methods used in the project are new tools for researching the influence of thermophysical and geometric parameters on a multicomponent mixture. Numerical modeling is based on the joint solution system of non-stationary equations of hydrodynamics, conservation of the number of mixture particles and components, taking into account the condition of independent diffusion and the equation of state. For numerical calculations, effective parallel numerical methods and algorithms will be used in the work, and results obtained will be compared with the calculated data of other authors and experimental results. Calculation of the test problems will be performed by the to prove the adequacy of the developed by mathematical models. Results of numerical modeling will be combined with experimental studies, which is an important methodological feature when performing tasks of this project.

  1. Aim of the project is: Numerical research of the mechanical equilibrium of isothermal triple gas mixtures, determination of the dynamic characteristics of the arising concentration gravitational flows under various conditions (pressure, mixture composition, ratio between diffusion coefficients), obtaining calculated data on the effect of cross-effects on the determination of the boundaries of the “diffusion – convection” transition. Conducting experiments to verify the results.
  2. Expected results: During the project development process, the following expected results will be obtained for the first time: 1. An analysis of the stability of mechanical equilibrium and development of computational algorithms will be carried out to determine the optimal thermobaric and concentration conditions of kinetic mixing regimes in multicomponent mixtures in which the diffusion regimes are changed to convective regimes; 2. Spectrum of thermophysical and geometric parameters that cause occurrence of supercritical flows in isothermal multicomponent gas mixtures will be determined; 3. Influence of diffusion mechanisms on the hydrodynamics of mixing multi-component systems getting used to a kinetic transition to the convective phase during mass transfer in cylindrical and flat channels will be studied; 4. Research generation of the initial phase of the supercritical flow in the pulsation regime at different pressures and initial compositions of multicomponent mixtures will be carried out; 5. Behavior of a convective structural formation located between two parallel solid surfaces in a medium of different density with taking into account the movement of the contact line along the solid surface will be studied;

Results achieved: An analysis of the stability of mechanical equilibrium is carried out and computational algorithms are developed, which allow determining the optimal thermobaric and concentration conditions of kinetic mixing regimes in multicomponent mixtures in which the diffusion regimes are changed to convective regimes. It is shown, that in triple gas mixtures, due to the different diffusion velocity of the components, conditions arise for the implementation of convection, which distorts the partial mass transfer expected during isothermal diffusion. It is established, that feature of the organization of concentration fields concluded on, that formed under the condition of a decrease in the density of the mixture with height. Within the framework of the stability theory, the solution of a system of hydrodynamic equations for an isothermal triple mixture is considered. For a flat vertical diffusion channel, a boundary relation is obtained, that allows predicting the transition from a diffusion state to a convective state for specific pVT conditions. Critical Rayleigh numbers for even and odd solutions are determined, also characteristic values for the convective mixing velocity are obtained. It is shown, that in the conditions of developed convection, change in the intensity of the transfer of components depending on the pressure is linked with the perturbation mode, that determines various types of convective flows. Work is being down to develop a model of the kinetic transition “diffusion-convection”. Critical Rayleigh numbers will be determined for a vertical cylindrical channel.

  1. The names and surnames of the members of research group with their identifiers (Scopus Author, Researcher ID, ORCID ID, if available) and links to the corresponding profiles:
  2. Project manager, Kosov Vladimir Nikolaevich (Researcher ID Web of Science: E-4057-2015; Scopus ID: 7003898941; ORCID ID:0000-0002-8001-1644) – doctor of physical and mathematical sciences, professor, corresponding member of the National Academy of Sciences of the Republic of Kazakhstan, foreign member of the Russian Academy of Natural Sciences, a well-known scientist in the field of gas physics. The Hirsch index for the Scopus and Web of Science citation databases is 6/4.
  3. Fedorenko Olga Vladimirovna (Researcher ID Web of Science: N-4847-2014), candidate of physical and mathematical sciences. Research activity: diffusion and convective heat and mass transfer in multicomponent systems. The Hirsch index for the Scopus and Web of Science citation databases is 5/3.
  4. Kulzhanov Dyusembek Uringalievich (Researcher ID Web of Scopus: 6506553349), doctor of physical and mathematical sciences, professor, project executor. Research activity: thermophysics, heat and mass transfer in gases. The Hirsch index for the Scopus and Web of Science citation databases is 2/3.
  5. Mukhamedenkyzy Venera (Researcher ID Web of Science: O-2430-2017), candidate of physical and mathematical sciences, project executor. Research activity: thermophysics, heat and mass transfer in gases. Author of more than 20 scientific papers. The Hirsch index for the Web of Science and Scopus citation databases is 2.
  6. Akzholova Aliya Abdirayymkyzy (Researcher ID Scopus: 563666282000), PhD, project executor. Research activity: thermophysics, architectonics of physical education. The Hirsch index for the Scopus and Web of Science citation databases is 2.
  7. Kalimov Adilet Bolatovich, master’s degree, PhD student of the third year, specialty “Physics”, project executor.
  8. Natalia Nikolaevna Khodarina, project executor. Research activity: radiation technologies, materials science. The Hirsch index for the Scopus and Web of Science citation databases is 2.
  9. Bondareva Polina Vladimirovna, project executor, Master’s degree.
  10. Zhussanbayeva Aiym Kanatovna, master’s degree, PhD student of the third year, project executor.
  11. List of publications (with links to them) and patents for the last 5 years
  12. Kossov V., Krasikov S., Fedorenko O. Diffusion and convective instability in multicomponent gas mixtures at different pressures // Eur. Phys. J. Spec. Top. – 2017. – Vol. 226, No. 6. – P. 1177-1187. https://doi.org/10.1140/epjst/e2016-60201-1
  13. Kossov V. , Fedorenko O., Zhakebayev D. Changing diffusion-convection modes in ternary mixtures with a diluent gas // Chem. Eng. Technol. – 2019. – Vol. 42, No. 4. – P 896-902. https://doi.org/10.1002/ceat.201800604.
  14. Kossov V., Zhakebayev D., Fedorenko O. Numerical mass transfer studies in case of convective flows occurrence in isothermal ternary gas mixtures // Comput. Thermal Scien. – 2019. – Vol. 11, No. 1. – 2. – P. 29-39. https://doi.org/10.1615/ComputThermalScien.2018024724.
  15. Kossov V.N., Fedorenko O.V., Zhakebayev D.B., Kizbaev A.P. Peculiarities of the rise of structured formations at the boundary of the change of the regimes “diffusion-concentration convection” at an isothermal mixing of a binary mixture equally diluted by the third component // Thermophys. and Aeromech. – 2019. – Vol. 26, № 1 – P. 27-35. https://doi.org/10.1134/S0869864319010049. (
  16. Zhavrin Y.I., Kosov V.N., Fedorenko O.V., Akzholova A.A. Some features of isothermal multicomponent mass transfer in the convective instability of gas mixture // Theor. Found. Chem. Engin. – 2016. – Vol. 50, No. 2. – P. 171-177. https://doi.org/10.1134/S0040579516020135.
  17. Asembaeva M.K., Kosov V.N., Krasikov S.A., Fedorenko O.V. Effect of the channel inclination angle on convective mixing caused by instability of mechanical equilibrium of ternary gas mixture at isothermal diffusion // Tech. Phys. Letters. – 2019. – Vol. 45, No. 11. – P. 1071-1074. https://doi.org/10.1134/S1063785019110038.
  18. Kosov V.N., Kul’zhanov D.U., Zhavrin Yu.I., Fedorenko O.V. Emergence of convective flows during diffusional mass transfer in ternary gas systems: The effect of component concentrations // Rus. J. Phys. Chem. A. – 2017. – Vol. 91, No. 6. – P. 984-989. https://doi.org/10.1134/S0036024417060127.
  19. Moldabekova M.S., Asembaeva M.K., Akzholova A.A. Experimental Investigation of the Instability of the Mechanical Equilibrium of a Four-Component Mixture with Ballast Gases // J. Engin. Phys. and Thermophys. – 2016. – Vol. 89, N2 – P. 417-421. https://doi.org/10.1007/s10891-016-1391-y
  20. Kosov V.N., Fedorenko O.V. Asembaeva M.K., Mukamedenkyzy V. Changing diffusion-convection modes in ternary mixtures with a diluent gas // Theor. Found. Chem. Engin. – 2020. – Vol. 54, No. 2. – P. 289-296. https://doi.org/10.1134/S0040579520020086.
  21. Косов В.Н., Кульжанов Д.У., Красиков С.А., Федоренко О.В., Калимов А.Б. Модернизация трехступенчатого разделительного модуля для газовых смесей в проточных устройствах // Вестник КазНПУ. Серия физ.- мат. – 2019. – № 2(66). – С. 170-174.
  22. Kosov V., Fedorenko O.V., Mukamedenkyzy V., Kalimov A.B Special modes of diffusion mass transfer in isothermal triple gas mixtures // Journal of Physics: Conference Series. 2020. Vol. 1565. 012061. doi:10.1088/1742-6596/1565/1/012061.

 

International patents included in the database Derwent Innovations Index

  1. Patent N EA30303-B1. Kosov V.N., Zhavrin Yu.I. Krasikov S.A., Fedorenko O.V. ID Derwent: 2019-23029. Derwent Primary Accession Number: 2019-230298. International Patent Classification: B01D-053/22. Publication Date 31 Jul 2018.

 

  1. Information for potential users: The project assumes studying the convective (diffusion) instability of a multicomponent mixture in model cavities of various geometric shapes under the initial condition of a decrease in the density of the mixture with height. Research will allow: to predict the spectrum of geometric and thermophysical parameters at which convective flows are formed in an isothermal multicomponent mixture, leading to synergetic transfer; to study the mechanisms of combined mass transfer in multicomponent mixtures with different properties and to develop new approaches to controlling the behavior of systems for specific tasks.

Scientific novelty of the project consists in the numerical and experimental research of the occurrence of structured flows at the boundary of the “diffusion – convection” transition for multicomponent gas systems in a wide range of pressures and initial compositions.

Numerically, it is assumed: to investigate the stability of a multicomponent mixture with different properties of diffusing components and nonlinear convection regimes at the initial stage of development; to study the effects of diffusion mechanisms and cross-diffusion effects on the mixing intensity during the kinetic transition to the convective phase of mass transfer; to calculate the distributions of component concentrations, pressure, and average velocity when supercritical convective flows occur at different ratios between diffusion coefficients, initial compositions, and other parameters for a specific channel geometry.

Experimentally, using the two-column method and diffusion bridge method, it is assumed to determine the boundaries of  “diffusion – convection” regime change and the intensity of supercritical flows at different pressures, initial compositions and geometric characteristics of the channel.

Researches of the diffusion and concentration gravitational convection areas in multicomponent systems are necessary, so that obtained results can be used to control movement of gas and gas mixtures in various technological processes. The results obtained for the first time can be used to select optimal solutions in the field of exhaust gas transport, which will contribute to reduce the environmental load on the environment.