Персона: Боговалов, Сергей Владимирович
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Институт нанотехнологий в электронике, спинтронике и фотонике
Институт ИНТЭЛ занимается научной деятельностью и подготовкой специалистов в области исследования физических принципов, проектирования и разработки технологий создания компонентной базы электроники гражданского и специального назначения, а также построения современных приборов на её основе.
Наша основная цель – это создание и развитие научно-образовательного центра мирового уровня в области наноструктурных материалов и устройств электроники, спинтроники, фотоники, а также создание эффективной инновационной среды в области СВЧ-электронной и радиационно-стойкой компонентной базы, источников ТГц излучения, ионно-кластерных технологий материалов.
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Сергей Владимирович
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- ПубликацияТолько метаданныеOptimal working regimes of the hyper-speed long Iguasu gas centrifuge(2020) Bogovalov, S. V.; Borman, V. D.; Vasilyev, A. V.; Tronin, I. V.; Tronin, V. N.; Боговалов, Сергей Владимирович; Васильев, Александр Владиславович; Тронин, Иван Владимирович© 2020 Published under licence by IOP Publishing Ltd.Rapid development of technologies for production of new materials may provide design of gas centrifuges (hereafter GC) with rotor speed above 1000 m/s. The question about efficiency of such GCs remains open. At present no experimental or theoretical studies regarding the separation effciency of such GCs exist. We present the results of calculations of the optimized separative power of the hyper-speed Iguassu GCs with a length of 1 to 5 meters and rotational speeds from 1000 to 1500 m/s. The calculations were performed in axisymmetric approximation in frameworks of the source-sink model. It is shown that for the hyper-speed GCs the optimized separative power, pressure at the rotor wall, feed flux and gas friction power linearly grow with the rotor length, while the temperature drop along the rotor does not depend on the rotor length.
- ПубликацияТолько метаданныеOptimized Separative Power of Hyperspeed Iguassu Gas Centrifuge: Dependence on the Rotor Diameter and Velocity(2020) Bogovalov, S. V.; Borman, V. D.; Tronin, I. V.; Tronin, V. N.; Боговалов, Сергей Владимирович; Тронин, Иван ВладимировичThe dependence of the separative power of Iguassu gas centrifuges (GCs) on the rotor diameter and velocity of rotation V above 1000 m/s is investigated. The separative power is calculated exploring numerical modeling of the gas dynamics and diffusion of the binary mixture in a strong centrifugal field. The separative power is optimized on five internal parameters of the GC: pressure at the wall of the rotor, feed flux, temperature drop along the rotor wall, friction power of the waste scoop and radius of the baffle of the product chamber. Enrichment of the product flux does not depend on the velocity and diameter in the optimal regime of exploration. Growth of the separative power withis determined by growth of the feed flux with the velocity.
- ПубликацияТолько метаданныеRatio of the jet power to the bolometric luminosity of the disk during accretion onto a black hole(2019) Bogovalov, S. V.; Боговалов, Сергей Владимирович© 2019 World Scientific Publishing Company. Disk accretion onto black holes is accompanied by collimated outflows (jets). In active galactic nuclei (AGN), the kinetic energy flux of the jet (jet power or kinetic luminosity) may exceed the bolometric luminosity of the disk by a few orders of magnitude. This may be explained in the framework of the so-called "cold" disk accretion when the only source of the AGN energy is the energy released by accretion. The radiation from the disk is suppressed because the disk wind carries out almost all the angular momentum and the gravitational energy of the accreting material. In this paper, we calculate the "unavoidable" radiation from the "cold" disk and the ratio of the kinetic energy power of the outflow to the bolometric luminosity of the accretion disk around a super massive black hole in the framework of the Shakura and Sunyaev paradigm of an optically thick α-disk. The exploration of the Fundamental Plane of Black Holes allows us to obtain equations that define the bolometric luminosity and the ratio of the luminosities as functions of the black hole mass and accretion rate. The application of our equations in the case of the M87 jet demonstrates good agreement with observations. In the case of Sgr A∗, these equations allow us to predict the kinetic energy flux from the disk around the Galactic supermassive black hole.
- ПубликацияТолько метаданные3-D Numerical Modeling of MHD Flows in an Aluminum Reduction Cell(2019) Pianykh, A. A.; Tkacheva, O. Y.; Radzyuk, A. Y.; Bogovalov, S. V.; Tronin, I. V.; Боговалов, Сергей Владимирович; Тронин, Иван Владимирович© 2019 IOP Publishing Ltd. All rights reserved.Three-dimensional numerical modeling of processes in an aluminum electrolytic cell at a current of 9 kA is performed. The model considers the nonlinear temperature dependence of all physical characteristics of materials. The specificity of the work is the inclusion in the model of the dynamics of the gas formed during the operation of the cell. The bubble motion, magnetic forces and heat convection essentially affect the overall dynamics of the electrolyte and metal. Calculations were carried out using the commercial software packages ANSYS CFX 18.2 and ANSYS Maxwell united with the aid of the user FORTRAN program.
- ПубликацияТолько метаданныеModelling Interaction of Relativistic and Nonrelativistic Flows on Adaptive Grids(2019) Koldoba, A. V.; Ustyugova, G. V.; Bogovalov, S. V.; Боговалов, Сергей Владимирович© 2019, Pleiades Publishing, Ltd. Abstract: We consider numerical aspects of the mathematical modeling of composite flows (relativistic and nonrelativistic) on adaptive computational grids applied to a double pulsar–optical star system. The pulsar is the source of an ultrarelativistic wind of the electron-positron plasma and the optical star is the source of a nonrelativistic wind. In the domains of relativistic and nonrelativistic flows, the plasma dynamics are described by different systems of equations. Moreover, the wind parameters are such that it is significantly difficult to model them in a similar way. Despite the fact that the distance between the partners of the binary system varies depending on the orbital phase, the flow is self-similar and is determined by the dimensionless parameters of the problem. The flow pattern can vary significantly under variations of these parameters. This requires the flexibility of the algorithm to construct a computational grid adaptable to the solution. In this work, we present the possibilities of use adaptive grids for modeling the above-mentioned class of composite flows.
- ПубликацияТолько метаданныеWinds from fast rotating stars(2021) Bogovalov, S. V.; Petrov, M. A.; Timofeev, V. A.; Боговалов, Сергей Владимирович; Петров, Максим АлександровичNumerical modelling of an isothermal wind from a fast rotating star is performed. Excitation of hydrodynamical turbulence and deviation of the shape of the stellar surface from a sphere are taken into account. Rotation and turbulence result in a dramatic increase of the mass flow rate from the star in comparison with a non-rotating one. The outflow occurs predominantly from a region on the stellar surface located at the equator. This flow expands rapidly due to thermal pressure. However, a disc-like flow at the equator is formed. The flow is more complicated near the pole. At large distances from the star a radially expanding wind is formed while close to the star some fraction of the outflow from the equatorial region falls down on to the stellar surface, producing a huge vortex. The dependence of the mass loss rate on the parameters of the star is presented.
- ПубликацияТолько метаданныеImpact of the vacuum core on the upper limit of the separative power of gas centrifuges(2021) Tronin, I. V.; Bogovalov, S. V.; Borman, V. D.; Tronin, V. N.; Тронин, Иван Владимирович; Боговалов, Сергей Владимирович© 2020 Elsevier LtdAccording to Dirac's equation the upper limit of the separative power of a gas centrifuge grows with rotation velocity V of the rotor as V4. This equation has two significant drawbacks. First, it was obtained assuming zero axial fluxes. Secondly, it does not take into account formation of a vacuum core near the axis of rotation. Its volume grows with the speed of rotation. Separation of isotopes does not occur in the vacuum core. In our work, we propose a new formulation of the problem of finding the upper limit of separative power without assumptions about zero axial flows and taking into account the limitation of the volume involved in the separation processes. According to our results, the upper limit of separative power increases with increasing speed much slower than the Dirac estimate, in proportion to V2.
- ПубликацияТолько метаданныеModeling of the wind/disk outflow from be stars(2021) Bogovalov, S.; Petrov, M.; Боговалов, Сергей Владимирович; Петров, Максим Александрович© 2021 by the authors. Licensee MDPI, Basel, Switzerland.The objective of this work is to reproduce the formation of the fast polar wind and viscous disk outflow from Be stars in a unified physical picture. Numerical modeling of the plasma outflow from fast rotating stars was performed taking into account the acceleration of the plasma due to scattering of the radiation of the star in lines of plasma ions and excitation of the hydrodynamic turbulence in the outflow. The fast polar wind naturally arises in this picture with an expected flow rate. For the first time, it is shown that a disk-like outflow with a relatively high level of turbulence is formed at the equator of fast rotating stars emitting radiation-driven wind. However, the level of turbulent viscosity is well below the level necessary for the formation of a Keplerian disk.
- ПубликацияТолько метаданныеPreface(2022) Bogovalov, S. V.; Боговалов, Сергей Владимирович
- ПубликацияТолько метаданныеModeling of the Wind/Disk Outflow from Be Stars II: Formation of the Keplerian Disk(2022) Bogovalov, S.; Petrov, M.; Боговалов, Сергей Владимирович; Петров, Максим АлександровичComputer modeling of the outflow from Be stars is performed. In our approach, processes of turbulence excitation and turbulent viscosity are added to the conventional model of the radiation driven winds. The objective of our study is to reproduce from the first principles the main features of the outflow from Be stars: a fast polar wind and a slow viscous Keplerian disk at the equator. At sub-critical velocity of rotation up to 0.999 of the critical velocity, our model reproduces the formation of the fast polar wind together with a slow highly turbulent outflow at the equatorial region. This outflow, however, does not reassemble a Keplerian disk. We link this to the absence of the angular moment transfer from the star to the disk. This process provides an increase of the angular momentum of the disk matter with radius. We consider a star with super critical rotation as the simplest way to supply the angular momentum to the disk. In this case, the star surface has a higher azimuthal speed than the matter at the inner edge of the disk. The angular momentum transfer becomes unavoidable. Already at rotation velocity 0.5% above the critical one, a quasi Keplerian disk at the equator is formed with size ∼10 stellar radius. At rotation 1% higher than the critical speed, the disk reaches ∼15 stellar radius. The main conclusion following from our work is that the conventional model of the radiation driven winds is able to reproduce the main features of the outflow from Be stars provided that the process of turbulence excitation and a process of angular momentum supply of the disk from the central source are added in to this model. © 2022 by the authors.
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