Galina Lazareva

Lazareva G.G., Arakcheev A.S., Popov V.A. Mathematical modeling of melting tungsten exposed to pulsed laser beam // Dokl. Math., 107:1 (2023), 83–87.

Melting in a tungsten plate exposed to a pulsed thermal load is numerically simulated by solving the two-phase Stefan problem. The free boundary is ignored during the calculation, since the numerical model is based on Samarskii’s approach. Calculations in axially symmetric geometry show that about a quarter of the incident energy is consumed by evaporation in the center of the melt region. This is five times more than estimates based on the solution of the one-dimensional heat equation. When tungsten evaporation is taken into account, the calculated and experimental cooling surface temperatures and radii of the melt region are in good agreement. The results of the mathematical modeling confirm the existence of an evaporation cooling mode when the tungsten is heated by an electron beam to temperatures significantly higher than the melting point.

Apushkinskaya D.E., Lazareva G.G., Okishev V.A. Influence of numerical diffusion on the growth rate of viscous fingers in the numerical implementation of the Peaceman model by the finite volume method // Contemporary Mathematics. Fundamental Directions, 68:4 (2022), 553–563 (in Russian).

A numerical model of oil displacement by a mixture of water and polymer based on the Peaceman model is considered. Numerical experiments were carried out using the DuMux package, which is a software library designed for modeling nonstationary hydrodynamic problems in porous media. The software package uses the vertex-centered variant of finite volume method. The effect of diffusion on the growth rate of “viscous fingers” has been studied. The dependencies of the leading front velocity on the value of model diffusion are obtained for three viscosity models. It is shown that the effect of numerical diffusion on the growth rate of “viscous fingers” imposes limitations on calculations for small values of model diffusion.

Lazareva G.G., Maksimova A.G. Numerical simulation of the propagation of tungsten vapor above a heated surface // Sibirskii Zhurnal Industrial'noi Matematiki, 25:3 (2022), 81–92 (in Russian).

The article presents numerical simulation results for the problem of tungsten vapor propagation after its evaporating from a surface heated with a high-speed electron beam. The model is based on solving a system of gas dynamics equations written in a divergent form. The resulting system of equations is implemented via the Belotserkovsky large particle method. The distributions of density and temperature of vapors are obtained for a surface heated up to temperature of 8000 K. Calculations show that normal temperature distribution on the sample surface leads to a noticably spherical shape of the gas exit front.

Apushkinskaya D.E., Lazareva G.G. Algorithm for the numerical solution of the Stefan problem and its application to calculations of the temperature of tungsten under impulse action // Contemporary Mathematics. Fundamental Directions, 67:3 (2021), 442–454 (in Russian).

In this paper, we present the numerical solution of the Stefan problem to calculate the temperature of the tungsten sample heated by the laser pulse. Mathematical modeling is carried out to analyze field experiments, where an instantaneous heating of the plate to 9000 K is observed due to the effect of a heat flow on its surface and subsequent cooling. The problem is characterized by nonlinear coefficients and boundary conditions. An important role is played by the evaporation of the metal from the heated surface. Basing on Samarskii's approach, we choose to implement the method of continuous counting considering the heat conductivity equation in a uniform form in the entire domain using the Dirac delta function. The numerical method has the second order of approximation with respect to space, the interval of smoothing of the coefficients is 5 K. As a result, we obtain the temperature distributions on the surface and in the cross section of the sample during cooling.

Lazareva G.G., Popov V.A., Arakcheev A.S., Burdakov A.V., Shwab I.V., Vaskevich V.L., Maksimova A.G., Ivashin N.E., Oksogoeva I.P. Mathematical simulation of the distribution of the electron beam current during pulsed heating of a metal target // Journal of Applied and Industrial Mathematics, 15:2 (2021) 292–301.

We study a model of the current distribution during heating of the surface of a tungsten sample under pulsed exposure to an electron beam. The model is based on solving the equations of electrodynamics and the two-phase Stefan problem for calculating the temperature in the sample region using a cylindrical coordinate system. The model parameters were taken from experiments at the «Beam of Electrons for materials Test Applications» (BETA) stand created at the Budker Institute of Nuclear Physics. A particular case of axial symmetry is considered without taking the electromotive forces into account. The current is considered as a possible source of rotation of the substance which is observed in the experiment. The values of the current and the acceleration of matter at a surface temperature of over 6000 K were obtained. The results of the performed simulation show that, to obtain an acceleration capable of initiating the experimentally observed rotation of the melt, it is necessary to take into account some alternative mechanisms of creating a current in the system with consideration of the evaporation of tungsten above the plate.

Vyacheslavov, Vasilyev A.A., Arakcheev A.S., Cherepanov D.E., Kandaurov I.V., Kasatov A.A., Popov V.A., Ruktuev A.A., Burdakov A.V., Lazareva G.G., Maksimova A.G., Shoshin A.A. In situ study of the processes of damage to the tungsten surface under transient heat loads possible in ITER // Journal of Nuclear Materials. Vol. 544, № 152669, 2020.

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.

Arakcheev A. S., Lazareva G. G., Maksimova A. G., Popov V. A., Ivashin N. E. Calculation of the expansion dynamics of evaporated tungsten under the action of a laser pulse // Journal of Physics: Conference Series, Vol. 1640, No. 012007, 2020, pp. 1-8.

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.

Vyacheslavov L.N., Vasilyev A.A., Arakcheev A.S., Cherepanov D.E., Kandaurov I.V., Kasatov A.A., Popov V.A., Ruktuev A.A., Burdakov A.V., Lazareva G.G., Maksimova A.G., Shoshin A.A. In situ study of the processes of damage to the tungsten surface under transient heat loads possible in iter // Journal of Nuclear Materials, Vol. 544б № 152669, 2020.

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.

Arakcheev A.S., Lazareva G.G., Maksimova A.G., Popov V.A., Ivashin N.E. Calculation of the expansion dynamics of evaporated tungsten under the action of a laser pulse // Journal of Physics: Conference Series. Vol. 1640, No. 012007, 2020, pp. 1-8.

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.

Lazareva G.G., Arakcheev A.S., Maksimova A.G., Popov V.A. Numerical model of evaporation of tungsten in vacuum under high-power transient heating // Journal of Physics: Conference Series (IOP), Vol. 1391, № 012074, 2019.

At the BETA installation, an electron beam is used to simulate pulsed thermal loads on the corresponding ITER tungsten. Numerical experiments are used to verify the models. In this paper, an extension of the electron beam heating model is presented, supplemented by the dynamics of gas evaporation from a heated surface in vacuum.

Lazareva G.G., Arakcheev A.S. , Popov V.A., Maksimova A.G. Estimation of the change in the gas flow rate from the surface of a tungsten plate under pulsed heat load // Journal of Physics: Conference Series (IOP). 2019. Vol. 1336, № 012011.

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.

Arakcheev A.S., Arakcheev S.A., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Lazareva G.G., Maksimova A.G., Mashukov V.I., Popov V.A., Trunev Y.A., Vasilyev A.A., Vyacheslavov L.N. On the mechanism of surface-parallel cracks formation under pulsed heat loads // Nuclear Materials and Energy, 2019, V. 20, № 100677.

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.

Lazareva G.G., Arakcheev A.S., Popov V.A., Maksimova A.G., Kapina E.S. Calculation of current distribution in tungsten plate under exposure to a pulsed electron beam // Journal of Physics: Conference Series, Vol. 1392, 012043, 2019.

A calculation of the current distribution in the medium has been added to the mathematical model of melting of a tungsten plate exposed to a pulsed electron beam. The model takes into account the heterogeneity of the resistivity. This makes it possible to simulate inhomogeneous heated material. It is expected that the current will spread to the depth due to the increased resistance of the heated part. By changing the thickness of the tungsten plate, it is possible to increase the current density in the melt. The results of calculations of parameters corresponding to the parameters used at the BETA installation of the Institute of Nuclear Physics. Budker SB RAS, show that current concentration does not occur. The ampere force is not large enough for the rotation observed in the experiments.

Lazareva G.G., Arakcheev A.S., Vasilyev A.A., Maksimova A.G. Numerical simulation of tungsten melting under fusion reactor-relevant high-power pulsed heating // Smart Innovation, Systems and Technologies, Vol. 133, 2019, pp. 41-51.

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.

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.

Sorokin S.B., Maksimova A.G., Lazareva G.G., Arakcheev A.S. Numerical implementation of the Lame equation with complex boundary conditions // Journal of Physics: Conference Series (IOP), Vol. 1336, № 012016, 2019.

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 V 100 a, a performance of 0.5 TFLOPS was achieved for 3D modeling of particles in cells. The article includes a brief description of the simulation algorithm, details of the implementation of the GPU and performance analysis with various GPUs.

Lazareva G.G., Arakcheev A.S., Popov V.A., Maksimova A.G., Kapina E.S. Calculation of current distribution in tungsten plate under exposure to a pulsed electron beam // Journal of Physics: Conference Series, Vol. 1392, № 012043, 2019.

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.

Lazareva G.G., Arakcheev A.S., Maksimova A.G., Popov V.A. Numerical model of evaporation of tungsten in vacuum under high-power transient heating // Journal of Physics: Conference Series (IOP), Vol. 1391, № 012074, 2019.

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.

Lazareva G.G., Arakcheev AS., Vasilyev A.A., Maksimova A.G. Numerical simulation of tungsten melting under fusion reactor-relevant high-power pulsed heating // Smart Innovation, Systems and Technologies, Vol. 133, 2019, pp. 41-51.

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.

Maksimova A.G., Arakcheev A.S., Lazareva G.G. Numerical model for calculating displacements near a crack // Journal of Physics: Conference Series (IOP), Vol. 1336, № 012005, 2019.

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.

Maksimova A.G., Lazareva G.G., Arakcheev A.S. The calculation of heating of various geometry of cracks formed under during pulsed heat load // Bulletin of CC: Computer Science, No. 42, NCC Publisher, Novosibirsk, 2018, pp. 29-34.

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.

Arakcheev A.S., Apushkinskaya D.E., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Lazareva G.G., Maksimova A.G., Popov V.A., Snytnikov A.V., Trunev Yu.A., Vasilyev A.A., Vyacheslavov L.N. Two-dimensional numerical simulation of tungsten melting in exposure to pulsed electron beam // Fusion Engineering and Design Volume 132, July 2018, P. 13–17.

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.

Lazareva G.G., Arakcheev A.S., Burdakov A.V., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Maksimova A.G., Popov V.A., Shoshin A.A., Snytnikov A.V., Trunev Yu. A., Vasilyev A. A., Vyacheslavov L. N. Numerical model of high-power transient heating of tungsten with considering of various erosion effects // IOP Conf. Series: Journal of Physics: Conf. Series, Vol. 1103, № 012001, 2018.

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.

Lazareva G.G., Arakcheev A.S., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Maksimova A.G., Popov V.A., Snytnikov A.V., Trunev Yu.A., Vasilyev A.A., Vyacheslavov L.N. Computational experiment for solution of the Stefan problem with nonlinear coefficients // AIP Conference Proceedings, Vol. 2025, № 080005, 2018.

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.

Maksimova A.G., Lazareva G.G., Arakcheev A.S. Calculation of displacements around the crack formed during pulsed thermal load // Bulletin of CC: Computer Science, No. 42, NCC Publisher, Novosibirsk, pp. 23-28, 2018.

Artemyev S.S., Korneev V.D., Lazareva G.G. Calculation of frequency characteristics of a stochastic model of shock wave dynamics by the Monte-Carlo method // Proceedings of the International conference "Computational Mathematics and Mathematical Geophysics", Novosibirsk, 2018, pp. 33-40.

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.

Maksimova A.G., Lazareva G.G., Arakcheev A.S. The calculation of heating of various geometry of cracks formed under during pulsed heat load // Bulletin of CC: Computer Science, No. 42, NCC Publisher, Novosibirsk, 2018, pp. 29-34.

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.

Maksimova A.G., Lazareva G.G., Arakcheev A.S. Calculation of displacements around the crack formed during pulsed thermal load // Bulletin of CC: Computer Science, No. 42, NCC Publisher, Novosibirsk, 2018, pp. 23-28.

This paper presents the results of mathematical modeling of the problem of elasticity theory. The problem consists in the calculation of a model problem in a two-dimensional formulation aimed at finding the displacements around a crack.

Lazareva G.G., Arakcheev A.S., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Maksimova A.G., Popov V.A., Snytnikov A.V., Trunev Yu.A., Vasilyev A.A., Vyacheslavov L.N. Computational experiment for solution of the Stefan problem with nonlinear coefficients // AIP Conference Proceedings,Vol. 2025, № 080005, 2018.

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.

Lazareva G.G., Arakcheev A.S., Kandaurov I.V., Kasatov A.A., Kurkuchekov V.V., Maksimova A.G., Popov V.A., Shoshin A.A., Snytnikov A.V., Trunev Yu.A., Vasilyev A.A., Vyacheslavov L.N. Calculation of heat sink around cracks formed under pulsed heat load // IOP Conf. Series: Journal of Physics: Conf. Series, Vol. 894, UNSP 012120, 2017.

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.

Lazareva G.G., Shishlenin M.A., Idiyatullin R.A., Fedorov E.A., Zavolzhsky V.B., Khlestov I.V. Direct and inverse problem of complex impact on the reservoir using the technology of thermogasochemical impact with binary mixtures // Proceedings of the International Conference "Computational and Applied Mathematics 2017", 2017, Novosibirsk.

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.

Lazareva G.G., Maksimova A.G. Comparative analysis of kinetic-consistent difference schemes with a number of grid methods for solving gas-dynamic equations // Proceedings of the International conference "Computational and Applied Mathematics 2017", 2017, Novosibirsk.

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.

Lazareva G.G., Arakcheev A.S., Kasatov A.A., Popov V.A., Vasiliev A.A., Vyacheslavov L.N., Kandaurov I.V., Kurkuchekov V.V., Trunaev, Shanin A.A. Calculation of heat sink near cracks formed under pulsed heat load // Proceedings of the International conference "Computational and Applied Mathematics 2017", 2017, Novosibirsk.

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.

Lazareva G.G., Arakcheev A.S., Kandaurov I.V., Kasatov AA., Kurkuchekov V.V., Maksimova A.G., Popov V.A., Shoshin A.A., Snytnikov A.V., Trunev Yu.A., Vasilyev A.A., Vyacheslavov L.N. Calculation of heat sink around cracks formed under pulsed heat load // IOP Conf. Series: Journal of Physics: Conf. Series, Vol. 894, UNSP 012120, 2017.

Experimental and numerical modeling of conditions causing intense erosion and expected to be implemented by an infusion reactor has been carried out. The effect of the corresponding pulsed thermal loads on tungsten was modeled using a powerful electron beam source. Mechanical destruction, melting and spraying of the material were observed. Laboratory experiments are accompanied by computational ones. The computational experiment allowed us to quantify the overheating near cracks caused by parallel surface cracks.

Lazareva G.G., Fedorov E.A., Idiyatullin R.A., Khlestov I.V., Zavolzhskiy V.B. Radial inflow model in the bottom zone of exploitation wells // Bulletin of Novosibirsk Computing Center: Numerical Analysis, No. 18, NCC Publisher, Novosibirsk, 2016, pp. 29-37.

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.

Lazareva G.G., Fedorov E.A., Idiyatullin R.A., Khlestov I.V., Zavolzhskiy V.B. Radial inflow model in the bottom zone of exploitation wells // Bulletin of Novosibirsk Computing Center: Numerical Analysis, No. 18, NCC Publisher, Novosibirsk, 2016, pp. 29-37.

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.

Berendeev E.A., Dimov G.I., Ivanov A.V., Dudnikova G. I., Ivanov A. V., Lazareva G. G., Vshivkov V. A. Mathematical and experimental simulation of a cylindrical plasma target trap with inverse magnetic mirrors // Journal of Plasma Physics October 2015, 81(05).

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.

Berendeev E.A., Dimov G.I., Ivanov A.V., Lazareva G.G., Fedoruk M.P. Simulation of Low_Temperature Multicomponent Plasmas in a Target Trap // Doklady Physics, Vol. 60, No. 2, 2015, pp. 1–4.

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.

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