1993

Graduated from the Faculty of Mathematics and Mechanics of Novosibirsk State University (FMM NSU), Bachelor's degree in “Mechanics and Applied Mathematics”.

1997

Master's degree in “Mathematics” at NSU was received.

2002 - present

Works at NSU, since 2013 - professor of the Department of Computational Mathematics of FMM NSU.

2002 - 2007

Academic Secretary of the Department of Mathematical Modeling of FMM NSU.

2003

Thesis on “Numerical modeling of shock wave amplification in bubble media” for the degree of Candidate of Physical and Mathematical Sciences was defended.

2004 - 2020

Research assistant (from junior researcher to chief researcher) at the Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences.

2008

The title of Associate Professor at the Department of Mathematical Modeling of FMM NSU was awarded.

2007 - 2016

Deputy Dean of FMM NSU.

2012

Thesis on “Mathematical simulation of multiphase gas dynamics taking into account gravity on a mainframe computer” for the degree of Doctor of Physical and Mathematical Sciences was defended.

2015 - 2021

Professor at the Department of Electrophysical Facilities and Accelerators of Novosibirsk State Technical University.

2015

Professor of the Russian Academy of Sciences, Department of Mathematical Sciences of the Russian Academy of Sciences, Section of Applied Mathematics and Computer Science.

2016

Corresponding Member of the Russian Academy of Sciences, Department of Mathematical Sciences of the Russian Academy of Sciences, Section of Applied Mathematics and Computer Science.

2016 - present

Member of the Editorial Board of the journal Numerical Analysis and Applications.

2019 - present

Professor of S.M. Nikol’skii Mathematical Institute of RUDN University.

Teaching

Gives the course of lectures to RUDN students of bachelor’s and master’s studies in the direction “Applied Mathematics and Computer Science”,

  • “Additional chapters of computational methods”,
  • “Analytical and numerical methods for hydrodynamic problems”,
  • “Mathematical models of continuous media”.

Science

  • Studied non-stationary processes in the problems of mechanics of multiphase compressible media and plasma physics as a result of the implementation of a full cycle of mathematical simulation. As a result, new optimal cost-effective algorithms with the highest possible degree of parallelizability, which take into account the specifics of the task were developed. For example, self-gravity consideration, highly variable coefficients, etc. Created software for mathematical simulation (a computational experiment verified by comparison with a physical experiment).
  • Studied the dynamics of plasma and the efficiency of its retention in a new type of plasma trap with a low-temperature plasma. The results of numerical calculations are already used: in the design of new plasma “target traps” with inversion plugs and in the development of installations on counter electron-positron and proton beams, particle accelerators.
  • Studied essentially nonlinear processes of shock wave amplification and fluid destruction in bubble (cavitating) media that develop under shock-wave loading. When calculating problems with a “bubble cluster”, discovered new physical effects that can be used to create a “saser” - an acoustic analog of pulsed laser systems.
  • Studied the evolution of gravitationally unstable systems in the earth: the dynamics of mantle flows and the mechanism of magma destruction during the “explosive nature” of depressurization of a volcanic channel. In addition, when calculating problems with self-gravity, possible mechanisms for the origin of new galaxies were discovered - this allows us to consider new cosmological hypotheses. Simulates the erosion of tungsten samples under the influence of thermal pulse loads.

Scientific interests

  • Mathematical simulation of the dynamics of multiphase compressible media;
  • Mathematical simulation of self-gravitating gas;
  • Mathematical simulation of plasma dynamics and efficiency of its retention;
  • Mathematical simulation of heating and evaporation of refractory metals.
The work is devoted to the numerical implementation of the tungsten evaporation process model. The tungsten evaporation model is based on solving the two-phase Stefan problem for temperature in the sample area and gas dynamics equations over the sample. The calculation results for parameters corresponding to those used on the BETA facility at BINP SB RAS show that it is possible to use the boundary homogeneous conditions of the Neumann for the velocity when setting the gas density on the plate surface.
This paper presents a model for calculating deformations and mechanical stresses around a crack normal to surface that appeared under pulsed heat load. The model was applied to calculation of stresses that may lead to formation of cracks along the surface, which are observed when tungsten is exposed to ITER-relevant heat load. It was found that such stresses might be not negligibly small in comparison with the ultimate tensile strength, and thus the appearance of cracks normal to the surface may leads to development of cracks parallel to the surface. The calculated deformation of the region around a crack is in good agreement with the experimental data. The deformations calculated can be a basis for experimental detection of formation of cracks normal and parallel to the surface.
Melting of the surface of tungsten exposed to a pulsed electron beam has been simulated numerically. Comparison of the experimentally measured at BETA facility time dependence of the radius of the molten region with the calculated data has shown that the surface cooling caused by evaporation has a significant effect on the temperature distribution and melting of the material at sufficiently high densities of the surface heating power. This result validates the created theoretical model of the tungsten melting and evaporation in exposure to a pulsed electron beam. The studied mechanism of the limitation of the surface temperature is different from the well-studied vapor shielding. The presented model is a step to correct interpretation of the erosion caused by the melt motion and splashing in exposure to the ITER-relevant pulsed heating by electron beam.
A plasma target for highly efficient neutralization of powerful negative ion beams is considered. The plasma is confined within a magnetic trap with multipole magnetic walls. It is proposed to use inverse magnetic mirrors to limit plasma outflow through the inlet and outlet holes in the trap. Using the particle-in-cell method, mathematical simulation of plasma dynamics in the trap has been performed. The estimates of plasma distribution and particle confinement efficiency in the region of the magnetic mirrors has been obtained. Simulation results were compared with experimental data.
The INP SB RAS proposed a magnetic trap with a weak longitudinal field and inverse plugs (with an inverse field). In a trap with a weak longitudinal field, it is advisable to limit the radial plasma losses by multipole magnetic walls of annular geometry. In an axisymmetric trap with annular magnetic surfaces, there is no azimuthal component of the field, as well as no stationary azimuthal electric field. The experiments are accompanied by calculations of the passage of the control plasma components (protons, atoms, negative ions) through the trap. A mathematical model of plasma dynamics in a trap is implemented in the form of a software package for a multiprocessor super-computer.
The paper reviews the problem of forecasting the possible maximum pressure at the well-head, at the well-bore and at near-wellbore zone of reservoir during the process of new stimulation technology like reactive chemistry application. The technology provides stimulation by thermobaric effects. This impact occurs as a result of thermal decomposition of a binary systems at different reservoir conditions.
Experimental and theoretical modeling of conditions that cause intense erosion and are formed during energy deposits and durations of exposure to the surface of tungsten, characteristic of pulsed processes in the ITER installation, was carried out. A high-power electron beam is used to simulate the corresponding pulsed thermal load in the modes with mechanical destruction, melting and spattering of the material. Laboratory experiments are accompanied by computational experiments. The computational experiment allowed us to quantify the overheating near cracks on the surface caused by cracks parallel to the surface.
The paper presents a direct and inverse problem of modeling a complex impact using the technology of thermogasochemical impact with binary components on wells. For the possibility of substantiating the parameters of the ongoing industrial tests, a high-speed calculation module has been developed for performing calculations by the technological services of the service enterprise. The inverse problem is set to obtain optimal values of the reagent injection volumes. An example of the application of a software package for the permocarboxylic deposit of the Usinsky field of LUKOIL-Komi is given, which shows the operational accuracy of the forecast of work on the complex impact on the bottom-hole zone of the productive formation by injected binary chemical systems (monofuel) based on inorganic salts.
In this paper, various modifications of discrete kinetic models describing a single-particle distribution function are considered and tested. The test solutions are compared with the solutions obtained by explicit methods for solving the gas dynamics equations. A counterexample is given, showing the need to take into account the sequence of derivation of the equations of the method used.
This paper presents a computer-aided simulation to calculate the heating of a tungsten plate with different crack geometries forming in the process of a pulsed thermal load. The results of model testing, numerical calculations and comparison with experimental data are presented. The dependence of the surface temperature on the location of cracks is shown.
In this paper, the Monte-Carlo method is used to study a model of shock wave dynamics defined by a system of stochastic partial differential equations. The interaction of shock waves of high intensity and duration with gas bubbles is investigated. For parametric analysis of numerical solutions, it is proposed to use frequency characteristics that generalize the solution of the parabolic equation. The results of numerical experiments conducted on the Novosibirsk cluster supercomputer NKS-1P at the Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences are presented.
The experimental and numerical simulations of the conditions causing the intensive erosion and expected to be realized infusion reactor were carried out. The influence of relevant pulsed heat loads to tungsten was simulated using a powerful electron beam source in BINP. The mechanical destruction, melting and splashing of the material were observed. The laboratory experiments are accompanied by computational ones. Computational experiment allowed to quantitatively describe the overheating near the cracks, caused by parallel to surface cracks.
A numerical solution to the two-phase direct Stefan problem is considered. The position of the phase boundary depends on discontinuous nonlinear coefficients. The aim of the study is to provide a detailed resolution of the heat flow deep into the material with a fine spatial grid step. As compared with the size of the tungsten plate, the heating depth is very small. The problem statement under consideration is multiscale. Further expansion of the model involves gas dynamics equations to simulate the dynamics of the liquid and gaseous phases of the metal. The effect of discontinuous time- and space-nonlinear coefficients and boundary conditions on the nature of the solution is shown. The thermal conductivity function has a great influence on the solution. Surface melting of tungsten under exposure to a pulsed electron beam was simulated numerically, the evaporation process taken into account. The calculation is based on the experimental time dependence of the absorbed power density. The results of the calculations correlate with the experimental data obtained on the experimental test facility BETA at BINP SB RAS.
Surface melting of tungsten under exposure to a pulsed electron beam was simulated numerically, the evaporation process taken into account. The calculation is based on the experimental time dependence of the total beam power. The model of the tungsten heating process is based on solving the two-phase Stefan problem. The position of the phase boundary depends on discontinuous time-and space-nonlinear coefficients and boundary conditions. The aim of the study is to provide a detailed resolution of the heat flow deep into the material with a fine spatial grid step. As compared with the size of the tungsten plate, the heating depth is very small. The problem statement under consideration is multiscale. Further expansion of the model involves taking into account microcracks. Micro-cracks occur during the cooling process after exposure and affect the temperature of the tungsten surface during the subsequent heating process. The article presents a modeling of cracks of different geometries typical for this process. The results of the calculations correlate with the experimental data obtained on the experimental test facility BETA at BINP SB RAS.
Surface melting of tungsten under exposure to a pulsed electron beam was simulated numerically, the evaporation process taken into account. The calculation is based on the experimental time dependence of the total beam power. The model of the tungsten heating process is based on solving the two-phase Stefan problem. The position of the phase boundary depends on discontinuous nonlinear coefficients. The aim of the study is to provide a detailed resolution of the heat flow deep into the material with a fine spatial grid step. As compared with the size of the tungsten plate, the heating depth is very small. The problem statement under consideration is multiscale. Further expansion of the model involves gas dynamics equations to simulate the dynamics of the liquid and gaseous phases of the metal. Two approaches to solving the equation for temperature are considered: the implicit run method and the explicitly solvable Konovalov-Popov model. The results of calculations correlate with the experimental data obtained at the experimental stand Beam of Electrons for materials Test Applications (BETA) at Budker Institute of Nuclear Physics (BINP) of the SB RAS.
A discrete model is constructed for calculating the Lame equation with complex boundary conditions. The model is tested on an analytical solution. A complex boundary condition arises when a microcrack is specified on one of the boundaries. Calculation of microcracks will enable better assessment of the relevance of the simulation and finding out which mechanisms will occur in the case of plasma flow heating in modern plasma and future thermonuclear installations.
Romanenko A. A., Snytnikov A. V., Lazareva G. G. High performance collisional PIC plasma simulation with GPU-based clusters // Journal of Physics: Conference Series, Vol. 1336, № 012005, 2019.
With the recent Nvidia Tesla V100 a performance of 0.5 TFLOPS was achieved for 3D Particle-In-Cell simulation. The paper includes brief description of the simulation algorithm, the detail of GPU implementation and the performance analysis with different GPUs.
In the mathematical model of melting of a tungsten plate exposed to a pulsed electron beam, the calculation of the current distribution in the medium is added. The model takes into account the heterogeneity of the resistivity. This enables modeling of non-uniform heated material. The current is expected to spread into the depth due to the increased resistance of the heated part. Changing the thickness of the tungsten plate, one can increase the current density in the melt. The calculation results for parameters corresponding to those used on the BETA facility at BINP SB RAS show that no current concentration occur. The Ampere force is not large enough for the rotation observed in the experiments.
On the BETA facility, an electron beam is used for simulation of pulsed thermal loads on ITER-relevant tungsten. Numerical experiments are used for verification of the models. This paper presents extension of the model of electron beam heating, supplemented with dynamics of gas evaporation from a heated surface in vacuum.
The paper presents a two-dimensional model of elastic deformations. An isotropic medium region in near a crack propagating along the surface is considered. The results correlate well with an analytical solution.
The paper is devoted to the numerical implementation of a model of the dynamics of the tungsten vapors flow evaporating from the sample surface. To calculate the speed and mass flow rate of the substance evaporating from the sample surface, a system of gas dynamics equations is numerically solved. The boundary conditions for the gas velocity and density on the heated surface have a great influence on the solution of the problem. Boundary conditions for temperature are obtained as a result of solving the two-phase Stefan problem in a cross-section of the sample. The aim of the study is to model the erosion of the sample surface and penetration of heat flow into the material.
Experiments on the effect of fast heat loads on the surface of tungsten were carried out on the BETA facility at the Budker Institute. Tungsten samples were uniformly heated by an electron beam with a heat flux factor below the melting threshold. During and shortly after exposure, the 2D surface temperature distribution was measured, as well as the temperature history on selected surface areas. Active diagnostics using the scattering of CW laser light on a surface exposed by the electron beam allowed us to monitor the damage dynamics. At the heating stage, an increase in the surface roughness occurred, caused by inhomogeneous elastic and plastic deformations of the heated layer. As the cooling progressed, the residual plastic deformations remained. Simultaneously with the modification of the surface, bending of samples with a thickness of 3-4 mm occurred. The bending dynamics of the sample was measured by the intensity of a converging laser beam reflected from the back surface of the sample, polished to a mirror state. The residual sag due to bending increases with the heat load similarly as residual roughness of the front surface of the sample. These data, together with simultaneously measured temperature dynamics and the spatial heating profile, can provide an experimental basis for the numerical calculation of the residual stresses in the sample. The data obtained in situ were compared with those measured outside the vacuum chamber with X-ray diffraction, optical profiler, and optical interferometer. At the stage of cooling, after a sufficient intensity of heating, the second stage of damage took place — the cracking of the surface layer. The time before the start of this relatively fast process usually exceeded the time to achieve a DBTT by 1–4 orders of magnitude.