Cosmic Gasdynamics group

The Physical Gasdynamics laboratory was formed in IPMech RAS in 1987 as a part of the Cosmic Gasdynamic department after its transfer from Space Research Institute (IKI) RAS. The department was founded and directed by academician George I. Petrov - the first director of IKI RAN. The laboratory takes leading positions in the world in theoretical modeling of physical phenomena in space. This leading position is connected with the pioneer work by Baranov, Krasnobaev and Kulikovskii (Dokl. AN SSSR, 1970, 194, p.41). In this work the model of interaction between the solar wind and supersonic flow of the interstellar medium has been proposed. The supersonic nature of the flow of the interstellar medium in the vicinity of the solar system was confirmed in 1971 in experiments at the American spacecraft OGO-5.

The first axisymmetric kinetic-continued model of the interaction of the solar wind and supersonic flow of partly ionized interstellar hydrogen plasma was developed in the laboratory (Baranov and Malama, J. Geophys. Res., 98, p. 15157, 1993). The model gave the most adequate description of the concerned physical effect. In the model the interaction of the solar wind with the charged component of the interstellar medium was described in the framework of continuum mechanics, while the interaction with atoms was described on the basis the kinetic gas theory. The figure shows general physical pattern of the flow obtained in the framework of the model. The interaction of the local interstellar medium (LISM) with the solar wind (SW) results in formation of the interface, including the outer shock layer (the region between the bow shock BS and tangential discontinuity HP called heliopause) and the inner shock layer (the region between the heliopause and solar wind termination shock TS). The influence of the calculated interface region on penetration of hydrogen, oxygen, nitrogen and other atoms from the interstellar medium in the solar system was recognized in the whole world owing to experiments at spacecraft Voyager 1/2, Pioneer 10/11, Ulysses, Hubble Space Telescope, SOHO and so on. The main obstacle for the penetration is the charge exchange process.

The very important prediction of the model is so called "hydrogen wall", i.e. nonmonotonic decrease of the interstellar H atom number density with a peak near the heliopause. The "hydrogen wall" was conformed experimentally in 1996 by Layman alpha absorption spectra from distant stars at well-known American spacecraft Hubble Space Telescope.

The model of interaction of the solar wind with the interstellar medium is modifying continuously by inclusion of new physical effects: heliolatitude dependence of the solar wind velocity, dynamical influence of galactic and anomalous cosmic rays, influence of the solar and interstellar magnetic fields, solar activity cycles, multi-component nature of the plasma flow and so on.

The crossing of the heliospheric termination shock by spacecraft Voyager 1 in December 2004 and Voyager 2 in August 2007 at 94 and 84 AU, respectively, was predicted theoretically in the frame of the model with high accuracy far before these events.

Experimental work in the field of physical kinetic and scientific instrument-making is also carried out in the group. This work is connected both with study of atomic collisions as applied to space phenomena and with construction of scientific instruments for aerospace probes to study planet atmospheres, interplanetary medium and the Earth by remote diagnostic at the aerospace probes.

Computational Hydro-aerodynamics group

The basic research themes of the group are connected with numerical modeling of turbulence flows and heat transfer in two-dimensional channels and three-dimensional unsteady boundary layers on complex form bodies. The more important points are processes of transition from laminar flow regimes to turbulent.

In this group two-level numerical technique for reacting dispersed flow is also developed. The approach is applied to research of formation of micro particles in high-temperature reacting gas-phase systems that are important for many practical problems, such, for example, as Chemical Vapor Deposition (CVD) technology.

International collaboration

The laboratory takes part in international programs and projects. The more important recent project is the cosmic mission NASA IBEX (Interstellar Boundary Explorer). From the middle of 80th the laboratory collaborates with Astronomical Institute of Bonn University on the subject "Physical processes in the heliosphere". The members of the laboratory maintain close contacts with Service d'Aeronomie CNRS (France), University of South California, International Space Science Institute (Bern), University of Sheffield (UK) and others.

Premiums and awards

Baranov V.B. - order "Symbol of honor" (1971), S.A. Chaplygin prize of RAS (1982), Y.A. Gagarin medal (1981), academician G.I. Petrov medal (2006), M.V. Keldysh medal (2007).

Izmodenov V.V. - Y.B. Zeldovich medal (COSPAR, 2006), I.I. Shuvalov prize (2006).

Main publications

1. Aleksin V.A., Zubarev V.M. Modeling of influence of parameters of turbulence of an incident flow on wall transition streams in the boundary layer, Matematicheskoe modelirovanie, v. 20, p.87-106, 2008 (in Russian).
2. Baranov V.B., Krasnobaev K.V., Kulikovski A.G. Model of interaction of the solar wind with interstellar medium, Dokl. AN SSSR, v. 194, p. 41, 1970 (in Russian).
3. Baranov V.B., Krasnobaev K.V. Hydrodynamic theory of cosmic plasma, Moscow, Nauka, 335 p., 1977 (in Russian).
4. Belov N.A. Instability of tangential discontinuity in a plane flow with critical point, Izv. RAN, Mech. zhidkosti i gaza, 2, p. 78-82, 1997 (in Russian).
5. Markov A.A. Numerical modeling of three-dimensional viscous flows by the march method with pressure global iterations, Izv. RAN, Mech. zhidkosti i gaza, 5, p. 132-147, 1992 (in Russian).
6. Aleksin V.A. Simulation of the effect of high-intensity turbulence flow parameters on unsteady boundary layer with streamwise pressure gradients, Fluid dynamics, v. 43, issue 2, p. 274, 2008.
7. Alexashov D.B., Chalov S.V., Myasnikov A.V., Izmodenov V.V., Kallenbach R. The dynamical role of anomalous cosmic rays in the outer heliosphere, Astron. Astrophys., v. 420, p. 729, 2004.
8. Alexashov D., Izmodenov V. Kinetic vs. multi-fluid models of H atoms in the heliospheric interface: a comparison, Astron. Astrophys., v. 439, p. 1171, 2005.
9. Baranov V.B., Lebedev M.G. Solar wind flow past a comet ionosphere, Astrophys. Space Sci., v. 147, p. 69, 1988.
10. Baranov V.B., Malama Yu.G., Model of the solar wind interaction with the local interstellar medium: numerical solution of the self-consistent problem, J. Geophys. Res. 98, 15157, 1993.
11. Belov N.A. Plasma flow in vicinity of the heliopause stagnation point in the presence of hydrogen neutral atoms, Astron. Letters, v. 36, 2, p. 144, 2010.
12. Chalov S.V., Alexashov D.B., McComas D., Izmodenov V.V., Malama Y.G., Schwadron N. Scatter-free pickup ions beyond the heliopause as a model for the Interstellar Boundary Explorer ribbon, Astrophys. J. Lett., v. 716, p. L99, 2010.
13. Izmodenov V.V., Gruntman M., Malama Yu.G. Interstellar hydrogen atom distribution function in the outer heliosphere, J. Geophys. Res., v. 106, p. 10681, 2001.
14. Izmodenov V.V., Alexashov D.B. A model for the tail region of the heliospheric interface, Astron. Letters, v. 29, p. 58, 2003.
15. Izmodenov, V.V., Malama, Y.G., Ruderman, M.S. Modeling of the outer heliosphere with the realistic solar cycle, J. Adv. Space Res., v. 41, Issue 2, p. 318-324 , doi:10.1016/j.asr.2007.06.033, 2008.
16. Malama Y.G., Izmodenov V.V., Chalov S.V. Modeling of the heliospheric interface: multi-component nature of the heliospheric plasma, Astron. Astrophys., v. 445, p. 693, 2006.
17. Markov A.A. Micro and macro scale technique for strongly coupled two-phase flows simulation, Comput. Fluids, v. 38.7, p. 1435-1444, 2009.
18. Myasnikov A.V., Alexashov D.B., Izmodenov V.V., Chalov S.V. Self-consistent model of the solar wind interaction with three-component circumsolar interstellar cloud: Mutual influence of thermal plasma, galactic cosmic rays, and H atoms, J.Geophys.Res., v. 105, p. 5167, 2000.
19. Nepobedimyi S.P., Rodionov I.D., Vorontsov D.V., et al. Hyperspectral remote sounding of the ground, Doklady Physics, v. 49, issue 7, p. 411, 2004.
20. Rylov Yu. A. Hydrodynamic equations for incompressible inviscid fluid in terms of generalized stream function, Int. J. Math. & Mat. Sci., v. 32, No. 11, pp. 541-570, 2004.

Laboratory staff