Труды сотрудников ИВМ СО РАН

[Text]. - Electronic data (133 Kb) : статья / A.N. Gorban, I.V. Karlin, V.B. Zmievskii, S.V. Dymova. - Electronic data (133 Kb) // Physica A. - 2000. - 275. - p. 361-379
   Перевод заглавия: Сокращение описания в химической кинетике
Аннотация: Models of complex reactions in thermodynamically isolated systems often demonstrate evolution towards low-dimensional manifolds in the phase space. For this class of models, we suggest a direct method to construct such manifolds, and thereby to reduce the effective dimension of the problem. The approach realizes the invariance principle of the reduced description, it is based on iterations rather than on a small parameter expansion, it leads to tractable linear problems, and is consistent with thermodynamic requirements. The approach is tested with a model of catalytic reaction.

http://icm.krasn.ru/refextra.php?id=2086,
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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Gorban, A.N.; Горбань, Александр Николаевич; Karlin, I.V.; Карлин, Илья Вениаминович; Zmievskii, V.B.; Змиевский В.Б.; Dymova, S.V.

[Text] : статья / A.N. Gorban [et al.] // Physica A. - 1996. - 231. - p. 648-672
   Перевод заглавия: Траектории релаксации: глобальная аппроксимация
Аннотация: The paper intends to fill the gap of analytic approximate methods for non-linear space-independent dissipative systems equipped with the entropy functional. The key point of the analysis is an upper limiting state in the beginning of the relaxation. Extremal properties of this state are described and explicit estimations are derived. This limiting state is used to construct explicit approximations of the phase trajectories. Special attention is paid to accomplish positiv-ity, smoothness and the entropy growth along the approximate trajectories. The method is tested for the space-independent Boltzmann equation with various collisional mechanisms.

http://icm.krasn.ru/refextra.php?id=2092,
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ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Gorban, A.N.; Горбань, Александр Николаевич; Karlin, I.V.; Карлин, Илья Вениаминович; Nonnenmacher, T.F.; Zmievskii, V.B.; Змиевский В.Б.

[Text] : статья / V. K. Andreev // Book of abstracts Sixth Int. conf. «Two-Phase Systems for Ground and Space Applications». - 2011. - p. 62


Доп.точки доступа:
Andreev V.K.

[Text] : статья / V. B. Bekezhanova, O. Kabov // Book of abstracts Sixth Int. conf. «Two-Phase Systems for Ground and Space Applications». - 2011. - p. 46


Доп.точки доступа:
Kabov, O.; Бекежанова, Виктория Бахытовна

[Текст] : статья / A.N. Rogalev // Optoelectronics, Instrumentation and Data Processing, Allerton Press. - 2011. - Vol. 47, Iss. 3. - p. 287-296, DOI 10.3103/S8756699011030125 . - ISSN 8756-6990
Аннотация: It is noted that, in many cases, object control is performed under conditions of a prior uncertainty in external actions and uncertainty in the current state of the object. Guaranteed methods are described which provide quantitative estimates of the boundaries of all possible phase states of a system taking into account all actions. Examples of calculations of inclusions of reachable sets are given.

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Рогалев, Алексей Николаевич

[Text] : статья / V. M. Sadovsky // Computational Plasticity XI. Fundamentals and Applications. - 2011. - p. 909-921 . - ISBN 978-84-89925-73-1

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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

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Садовский, Владимир Михайлович; International Conference on Computational Plasticity. Fundamentals and Applications(XI ; 07-09 September 2011 ; Barcelona)

[Text] / S.N. Genova [et al.] // Aquat. Ecol. - 2010. - Vol. 44, Is. 3. - pp. 571-584, DOI 10.1007/s10452-010-9327-7. - Cited References: 26. - The study was financially supported by the Netherlands Organization for Scientific Research (NOW), Grant 047.011.2004.030; RFBR, Grant 05-05-89002; RFBR, Grant 07-01-00153; Multidisciplinary integration project of SB RAS No. 95. . - ISSN 1386-2588РУБ Ecology + Limnology + Marine & Freshwater Biology

Аннотация: In meromictic lakes such as Lake Shira, horizontal inhomogeneity is small in comparison with vertical gradients. To determine the vertical distribution of temperature, salinity, and density of water in a deep zone of a Lake Shira, or other saline lakes, a one-dimensional (in vertical direction) mathematical model is presented. A special feature of this model is that it takes into account the process of ice formation. The model of ice formation is based on the one-phase Stefan problem with the linear temperature distribution in the solid phase. A convective mixed layer is formed under an ice cover due to salt extraction in the ice formation process. To obtain analytical solutions for the vertical distribution of temperature, salinity, and density of water, we use a scheme of vertical structure in the form of several layers. In spring, the ice melts as top and bottom. These processes are taken into account in the model. The calculated profiles of salinity and temperature of Shira Lake are in good agreement with field measurement data for each season. Additionally, we focussed on the redox zone, which is the zone in which the aerobic layers of a water column meet the anaerobic ones. Hyperactivity of plankton communities is observed in this zone in lakes with hydrogen sulphide monimolimnion, and Lake Shira is among them. The location of the redox zone in the lake, which is estimated from field measurements, coincides with a sharp increase in density (the pycnocline) during autumn and winter. During spring and summer, the redox zone is deeper than the pycnocline. The location of pycnocline calculated with the hydro physical model is in good agreement with field measurement data.


Доп.точки доступа:
Genova, S.N.; Генова, Светлана Николаевна; Belolipetskii, V.M.; Белолипецкий, Виктор Михайлович; Rogozin, D.Y.; Degermendzhy, A.G.; Mooij, W.M.

[Text] / U.V. Amerstorfer [et al.] // Phys. Plasmas. - 2010. - Vol. 17, Is. 7. - Ст. 72901, DOI 10.1063/1.3453705. - Cited References: 26. - This work was supported by the FWF under Project No. P21051-N16 and also by the RFBR under Grant No. 09-05-91000-ANF_a. . - ISSN 1070-664XРУБ Physics, Fluids & Plasmas

Аннотация: Results of two-dimensional nonlinear numerical simulations of the magnetohydrodynamic Kelvin-Helmholtz instability are presented. A boundary layer of a certain width is assumed, which separates the plasma in the upper layer from the plasma in the lower layer. A special focus is given on the influence of a density increase toward the lower layer. The evolution of the Kelvin-Helmholtz instability can be divided into three different phases, namely, a linear growth phase at the beginning, followed by a nonlinear phase with regular structures of the vortices, and finally, a turbulent phase with nonregular structures. The spatial scales of the vortices are about five times the initial width of the boundary layer. The considered configuration is similar to the situation around unmagnetized planets, where the solar wind (upper plasma layer) streams past the ionosphere (lower plasma layer), and thus the plasma density increases toward the planet. The evolving vortices might detach around the terminator of the planet and eventually so-called plasma clouds might be formed, through which ionospheric material can be lost. For the special case of a Venus-like planet, loss rates are estimated, which are of the order of estimated loss rates from observations at Venus. (C) 2010 American Institute of Physics. [doi:10.1063/1.3453705]


Доп.точки доступа:
Amerstorfer, U.V.; Erkaev, N.V.; Еркаев, Николай Васильевич; Taubenschuss, U.; Biernat, H.K.

[Text] / U. Taubenschuss [et al.] // Ann. Geophys. - 2010. - Vol. 28, Is. 5. - pp. 1075-1100, DOI 10.5194/angeo-28-1075-2010. - Cited References: 92. - The author appreciates financial support on behalf of the projects 06/9690 from the Austrian Research Community and A3-12T63/2007-1 from the Styrian government. Participation at the ISSS8 was made possible due to the travel fellowship of UCLA. Nikolai Erkaev acknowledges support by RFBR grants Nos. 07-05-00135 and 09-05-91000-ANF. Charles Farrugia received NASA grants NNG06GD41G and NNX08AD11G. Christian Mostl and Ute Amerstorfer work under FWF projects P20145N16 and P21051-N16 of the Austrian Science Foundation, respectively. . - ISSN 0992-7689РУБ Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We investigate the propagation of magnetic clouds (MCs) through the inner heliosphere using 2.5-D ideal magnetohydrodynamic (MHD) simulations. A numerical solution is obtained on a spherical grid, either in a meridional plane or in an equatorial plane, by using a Roe-type approximate Riemann solver in the frame of a finite volume approach. The structured background solar wind is simulated for a solar activity minimum phase. In the frame of MC propagation, special emphasis is placed on the role of the initial magnetic handedness of the MC's force-free magnetic field because this parameter strongly influences the efficiency of magnetic reconnection between the MC's magnetic field and the interplanetary magnetic field. Magnetic clouds with an axis oriented perpendicular to the equatorial plane develop into an elliptic shape, and the ellipse drifts into azimuthal direction. A new feature seen in our simulations is an additional tilt of the ellipse with respect to the direction of propagation as a direct consequence of magnetic reconnection. During propagation in a meridional plane, the initial circular cross section develops a concave-outward shape. Depending on the initial handedness, the cloud's magnetic field may reconnect along its backside flanks to the ambient interplanetary magnetic field (IMF), thereby losing magnetic flux to the IMF. Such a process in combination with a structured ambient solar wind has never been analyzed in detail before. Furthermore, we address the topics of force-free magnetic field conservation and the development of equatorward flows ahead of a concave-outward shaped MC. Detailed profiles are presented for the radial evolution of magnetoplasma and geometrical parameters. The principal features seen in our MHD simulations are in good agreement with in-situ measurements performed by spacecraft. The 2.5-D studies presented here may serve as a basis under more simple geometrical conditions to understand more complicated effects seen in 3-D simulations.


Доп.точки доступа:
Taubenschuss, U.; Erkaev, N.V.; Еркаев, Николай Васильевич; Biernat, H.K.; Farrugia, C.J.; Mostl, C.; Amerstorfer, U.V.

[Text] / A. P. Gavrilyuk, N. Y. Shaparev // Quantum Electron. - 2013. - Vol. 43, Is. 10. - P943-948, DOI 10.1070/QE2013v043n10ABEH015141. - Cited References: 18 . - ISSN 1063-7818РУБ Engineering, Electrical & Electronic + Physics, Applied

Аннотация: By means of numerical modelling of the combined effect of laser (1.06 mu m) and microwave (10(10)-10(13) s(-1)) radiation on the aluminium surface in vacuum it is shown that the additional action of microwave radiation with the frequency 10(12) s(-1) provides complete ionisation of the metal vapour (for the values of laser radiation duration and intensity used in the calculations), while in the absence of microwave radiation the vapour remains weakly ionised. The mathematical model used accounts for the processes, occurring in the condensed phase (heat conduction, melting), the evaporation and the kinetic processes in the resulting vapour.


Доп.точки доступа:
Shaparev, N.Ya.; Шапарев, Николай Якимович; Гаврилюк, Анатолий Петрович

[Text] / B.Harris [et al.] // Ann. Geophys. - 2013. - Vol. 31, Is. 10. - P1779-1789, DOI 10.5194/angeo-31-1779-2013. - Cited References: 26. - Work at UNH is supported by NASA Grants NNX10AQ29G and NNX13AP39G. N. V. Erkaev is supported by grant No. 12-05-00152-a from the Russian Foundation of Basic Research. . - ISSN 0992-7689РУБ Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: Acceleration of magnetosheath plasma resulting from the draping of the interplanetary magnetic field (IMF) around the magnetosphere can give rise to flow speeds that exceed that of the solar wind (V-SW) by up to similar to 60%. Three case event studies out of 34 identified events are described. We then present a statistical study of draping-related accelerations in the magnetosheath. Further, we compare the results with the recent theory of Erkaev et al. (2011, 2012). We present a methodology to help distinguish draping-related accelerations from those caused by magnetic reconnection. To rule out magnetopause reconnection at low latitudes, we focus mainly on the positive B-z phase during the passage of interplanetary coronal mass ejections (ICMEs), as tabulated in Richardson and Cane (2010) for 1997-2009, and adding other events from 2010. To avoid effects of high-latitude reconnection poleward of the cusp, we also consider spacecraft observations made at low magnetic latitudes. We study the effect of upstream Alfven Mach number (M-A) and magnetic local time (MLT) on the speed ratio V/V-SW. The comparison with theory is good. Namely, (i) flow speed ratios above unity occur behind the dawn-dusk terminator, (ii) those below unity occur on the dayside magnetosheath, and (iii) there is a good general agreement in the dependence of the V ratio on M-A.


Доп.точки доступа:
Harris, B.; Farrugia, C.J.; Erkaev, N.V.; Еркаев, Николай Васильевич; Torbert, R.B.; NASA [NNX10AQ29G, NNX13AP39G]; Russian Foundation of Basic Research [12-05-00152-a]

[Текст] : статья / V. M. Sadovskii, O. V. Sadovskaya, K. S. Svobodina // Journal of Siberian Federal University. Mathematics & Physics. - 2013. - Vol. 6, Iss. 3. - p. 342-348
   Перевод заглавия: Анализ дисперсии гидроакустических волн на основе модели вязкоупругой среды
Аннотация: On the basis of mathematical model of the Poynting–Thomson viscoelastic medium the effect of acoustic dispersion of water is described: the phase velocity of waves of terahertz frequency is doubled in comparison with the velocity of waves of sound range. Rheological parameters of the model are selected by means of the values of the velocities of propagation of slow and fast monochromatic waves. The system of equations of the dynamics of the Poynting–Thomson viscoelastic medium is reduced to the form, hyperbolic by Friedrichs. It guarantees the correctness of the Cauchy problem and boundary value problems with dissipative boundary conditions, and also allows to use the monotone grid-characteristic schemes for numerical solution of problems. In the framework of 1D model the computations of a transformation of hydroacoustic waves, generated by U-shaped impulse of pressure, were performed. Results of computations show a strong damping of the fast precursor as it passes the distance of hundred nanometers from the moment of entry and the emergence of stable profile of the slow wave at the mesolevel.

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Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Svobodina, K.S.; Садовский, Владимир Михайлович

[Text] / C. J. Farrugia [et al.] // SPACE WEATHER 2000. Ser. ADVANCES IN SPACE RESEARCH-SERIES : PERGAMON-ELSEVIER SCIENCE LTD, 2003. - Vol. 31: PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly (JUL, 2000, WARSAW, POLAND), Is. 4. - P1105-1110, DOI 10.1016/S0273-1177(02)00889-X. - Cited References: 16 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: With its similar to12 h-long period of strongly northward magnetic field, the coronal mass ejection which passed Earth on April 11, 1997 affords an excellent opportunity of studying Kelvin-Helmholtz (KH) activity at the dayside magnetopause as a function of the clock angle, theta, of the interplanetary field (IMF). A correlation between the wavelength of the KH waves and theta may be expected on the basis of our recent model, where activity is generated in strips which broaden as theta decreases. We identify two 2-hour long intervals of small, but different, clock angles, and make a preliminary test of model predictions, using records from two ground magnetometer chains, both on the dayside. Taking into account the local time of the magnetometer arrays and the geometry of the KH-active strips, we show that the resonant stations measured considerably more spectral power density in the 3-4 mHz range during the phase with smaller theta. Moreover, as theta increases, the spectral power spectrum shifted to higher frequencies that were almost absent for smaller theta. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.


Доп.точки доступа:
Farrugia, C.J.; Gratton, F.T.; Torbert, R.B.; Bender, L.; Gnavi, G.; Ogilvie, K.W.; Erkaev, N.V.; Еркаев, Николай Васильевич; Lepping, R.P.; Stauning, P.

[Text] / L. I. Shkutin // J. Appl. Mech. Tech. Phys. - 2008. - Vol. 49, Is. 2. - P330-335, DOI 10.1007/s10808-008-0045-z. - Cited References: 8 . - ISSN 0021-8944РУБ Mechanics + Physics, Applied

Аннотация: A mathematical formulation is given of nonlinear axisymmetric buckling problems for plates and shells in the two-phase zones of austenite-to-martensite transformation. Numerical solutions of the direct- and inverse-transformation problems are used to construct hysteresis loops for thermomechanically cycled, pressure-loaded circular plates and shallow spherical domes of titanium nickelide (NiTi) alloy. It is shown that dynamic instability of the dome deformation process can occur during transformation under loads notably lower than the upper critical values for the isothermal states of the material outside the transformation zone. A theoretical analysis gives external loads below which the dome remains stable in the thermally cycled material with phase transformations.


Доп.точки доступа:
Шкутин, Леонид Иванович

[Text] : статья / Y. Gaponenko, A. Mialdun, V. Shevtsova // International Journal of Multiphase Flow. - 2012. - Vol. 39. - p. 205-215, DOI 10.1007/s12217-008-9075-7 . - ISSN 0938-0108
Аннотация: Experiments and numerical simulations were carried out for shear-driven two-phase flows in a confined volume of liquid under conditions of normal gravity. The geometry corresponds to a cylindrical liquid bridge surrounded by a concentric annular gas channel with external solid walls. The internal part consists of solid supports at the bottom and top, while the central part is a liquid zone filled with a viscous liquid and kept in its position by surface tension. Gas enters into the annular duct, flows between solid walls and upon reaching the liquid zone entrains initially quiescent liquid. The flow dynamics is governed by the Navier–Stokes equations in both fluids, which are numerically solved in the exact experimental geometry taking into account interface deformation by gravity. In the experiments 5 cSt silicone oil and air were used as test fluids and the flow was monitored by means of particle tracking velocimetry. The experiments were performed for unit aspect ratio (the ratio of liquid zone length to its radius), while the simulations of shear-driven flow were carried out for a wide range of parameters. A particular attention is focused on the effect of free surface shape and fluids viscosity contrast on the interfacial flow dynamics. The current study suggests a linear dependence between velocities of gas and liquid when the viscosity of the liquid is larger by two orders of magnitude than that of gas. Another relation is proposed when the fluids viscosity ratio, μl/μg, is less than 50.

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Доп.точки доступа:
Mialdun, A.; Shevtsova, V.; Гапоненко, Юрий Анатольевич

[Text] : статья / Y. Gaponenko, A. Mialdun, V. Shevtsova // The European Physical Journal Special Topics. - 2011. - Vol. 192, Iss. 1. - p. 63-70, DOI 10.1140/epjst/e2011-01360-0 . - ISSN 1951-6355
Аннотация: We report the results of numerical and experimental studies of two-phase flows in an annulus. The geometry corresponds to a cylindrical liquid column co-axially placed into an outer cylinder with solid walls. Gas enters into the annular duct and entrains the initially quiescent liquid. The internal column consists of solid rods at the bottom and top, while the central part is a liquid bridge from a viscous liquid and kept in its position by surface tension. Silicone oil 5cSt was used as a test liquid and air and nitrogen as gases. An original numerical approach was developed to study the problem in complex geometry. The flow structure in the liquid is analyzed for a wide range of gas flow rates.

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Доп.точки доступа:
Mialdun, A.; Shevtsova, V.; Гапоненко, Юрий Анатольевич

[Text] : статья / Y. Gaponenko, S. Glockner, A. Mialdun, V. Shevtsova // Acta Astronautica. - 2011. - Vol. 69, Iss. 3-4. - p. 119-126DOI 10.1016/j.actaastro.2011.03.012 . -
Аннотация: We report on numerical and experimental study of two-phase flows in a tall annulus. The geometry corresponds to a cylindrical liquid column co-axially placed into an outer cylinder with solid walls. The internal column consists of solid supports at the bottom and top, while the central part is a liquid zone filled with viscous liquid and kept in its position by surface tension. Gas enters into the annular duct and entrains initially quiescent liquid. The liquid bridge interface is deformed by gravity and by a co-axial gas flow which is co- and counter directed with respect to gravity. A new experimental set-up including an optical system for precise measurements of the interface displacement has been designed and developed. In the experiments silicone oil 5cSt was used as a test liquid and air as gas. On numerical side the dynamical response of an isothermal liquid bridge to a coaxial gas flow is examined by simulations of the Navier–Stokes equations. The attention is focused on the following points: time-dependent formation of the equilibrium shape of a liquid bridge in gravity conditions and its deformation by a gas flow, simulation of a flow pattern in a liquid/gas system with deformed free surface. The comparison of the numerical and experimental results for the interface deformation exhibits a satisfactory agreement.

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Доп.точки доступа:
Glockner, S.; Mialdun, A.; Shevtsova, V.; Гапоненко, Юрий Анатольевич

[Text] / U. V. Mostl [et al.] // Icarus. - 2011. - Vol. 216, Is. 2. - P476-484, DOI 10.1016/j.icarus.2011.09.012. - Cited References: 27. - This work is supported by the Austrian Science Fund Project P21051-N16 and also by RFBR Grant No. 09-05-91000-ANF_a. H.L. and H.G. are supported by the Helmholtz Association through the research alliance "Planetary Evolution and Life" and by the Austrian Science Fund Project I199-N16. M.Z. and D.K. are supported by the Austrian Science Fund Project I193-N16. . - ISSN 0019-1035РУБ Astronomy & Astrophysics

Аннотация: The Kelvin-Helmholtz instability gained scientific attention after observations at Venus by the spacecraft Pioneer Venus Orbiter gave rise to speculations that the instability contributes to the loss of planetary ions through the formation of plasma clouds. Since then, a handful of studies were devoted to the Kelvin-Helmholtz instability at the ionopause and its implications for Venus. The aim of this study is to investigate the stability of the two instability-relevant boundary layers around Venus: the induced magnetopause and the ionopause. We solve the 2D magnetohydrodynamic equations with the total variation diminishing Lax-Friedrichs algorithm and perform simulation runs with different initial conditions representing the situation at the boundary layers around Venus. Our results show that the Kelvin-Helmholtz instability does not seem to be able to reach its nonlinear vortex phase at the ionopause due to the very effective stabilizing effect of a large density jump across this boundary layer. This seems also to be true for the induced magnetopause for low solar activity. During high solar activity, however, there could occur conditions at the induced magnetopause which are in favour of the nonlinear evolution of the instability. For this situation, we estimated roughly a growth rate for planetary oxygen ions of about 7.6 x 10(25) s(-1), which should be regarded as an upper limit for loss due to the Kelvin-Helmholtz instability. (C) 2011 Elsevier Inc. All rights reserved.


Доп.точки доступа:
Mostl, U.V.; Erkaev, N.V.; Еркаев, Николай Васильевич; Zellinger, M.; Lammer, H.; Groller, H.; Biernat, H.K.; Korovinskiy, D.

[Text] : тезисы / Y. Gaponenko, A. Nepomnyashchy, V. Shevtsova // Abstracts of 6-th Int. conf. on two-phase systems for ground and space applications. - 2011. - p. 54


Доп.точки доступа:
Nepomnyashchy, A.; Shevtsova, V.; Гапоненко, Юрий Анатольевич

[Text] : тезисы / V. Shevtsova [et al.] // Abstracts of 6-th Int. conf. on two-phase systems for ground and space applications. - 2011. - p. 39


Доп.точки доступа:
Shevtsova, V.; Mialdun, A.; Melnikov, D.; Gaponenko, Y.; Гапоненко, Юрий Анатольевич; Legros, J.C.