Vestnik of Samara University. Natural Science Series

The Journal is published four times a year

Editor-in-Chief

  • Andrey B. Prokof'ev, Doctor of Science (Engineering), associate professor
    ORCID iD: 0000-0002-8105-1752

Publisher & Founder

About

Journal «Vestnik Samarskogo universiteta. Estestvennonauchnaya seriya / Vestnik of Samara University. Natural Science Series» is a scientific edition, where the results of original research on sections: Mathematics; Physics; Mathematical Modelling; Mechanics; Mathematical Methods in Natural Sciences; Informatics and Computer Science are published. The journal is included by the Higher Attestation Commission in the List of leading scientific journals and publications in the Russian Federation, where basic scientific results of doctoral theses should be published since 2003, as included in the international database zbMATH and MathSciNet.

The mission of the journal is to highlight scientific ideas and results of original scientific research in the fields of mathematics, physics, mathematical modeling, mechanics, mathematical methods in the natural sciences, and information and computing systems among both the Russian-speaking audience and the foreign scientific community.

The goals and objectives of the journal: publication of results of original scientific research (scientific articles, scientific surveys, scientific reviews, brief scientific communications) in the field of physical and mathematical sciences; organization of interaction between Russian and foreign authors to carry out joint research and strengthen intercountry relations; promotion of the journal on the Russian and international market, including through indexing in Russian and international databases.

Publications

  • NO APC, NO ASC
  • Open Access with CC BY International license
  • Russian & English, German and French

Indexation


Current Issue

Vol 30, No 4 (2024)

Cover Page

Full Issue

Mathematics

Boundary value problems for discontinuously loaded parabolic equations
Karmokov M.M., Nakhusheva F.M., Gekkieva S.K.
Abstract

The article deals with boundary value problems for a discontinuously loaded parabolic equation with a Riemann – Liouville fractional integro-differentiation operator with variable coefficients. The unambiguous solvability of the Cauchy – Dirichlet problem for a discontinuously loaded parabolic equation of fractional order is proved. The paper also examines the existence and uniqueness of the solution of the first boundary value problem for a discontinuously loaded parabolic equation. Using the method of the Green function, using the properties of the fundamental solution of the corresponding homogeneous equation, as well as assuming that the coefficients of the equation are bounded, continuous and satisfy the Helder condition, while remaining non-negative, it is shown that the solution of the problem is reduced to a system of Volterra integral equations of the second kind.

Vestnik of Samara University. Natural Science Series. 2024;30(4):7-17
pages 7-17 views

Mechanics

Multiparametric presentation of the crack-tip fields in the vicinity of longitudinal shear crack
Bakhareva Y.N.
Abstract

The article is devoted to the study of the stress field at the tip of a longitudinal shear crack based on a multiparametric asymptotic representation of the stress field at the crack tip in a linearly elastic isotropic material. The performed asymptotic analysis of the fields at the tip of a longitudinal shear crack is a natural continuation of the studies conducted for multiparametric stress fields at the tips of cracks of normal separation and transverse shear, as well as mixed loading. Despite the simplicity of analyzing the contribution of higher approximations to the general representation of the stress field at the tip of a type III crack, multicoefficient representations of the stress field near this type of crack have not been previously studied. It is shown that higher-order approximations must necessarily be taken into account for 1) accurate representation of the stress field and 2) expansion of the range of asymptotic expansions. It has been found that the greater the distance from the crack tip, the more components of the series must be stored near the crack tip.

Vestnik of Samara University. Natural Science Series. 2024;30(4):18-25
pages 18-25 views
Solution of the Föppl – von Kármán equations for square plates
Digilov A.V., Lychev S.A.
Abstract

The present paper develops an approach to obtaining solutions of the Föppl – von Kármán equations for square plates, which are based on direct algebraisation of the boundary-value problem. The solution is obtained in term of expansion into basis of the space of square-integrable function. The system of eigenfunction of a linear self-adjoined operator is used as the basis. The expansion coefficients are defined by the reduction method from an infinite-dimensional system of cubic equations. It allows one to consider the proposed solution as non-linear generalisation of classic Galerkin method

Vestnik of Samara University. Natural Science Series. 2024;30(4):26-45
pages 26-45 views
Experience in developing jet noise silencers
Kalabukhov V.N.
Abstract

In this paper, we investigate the acoustic characteristics of subsonic jet streams exposed to high-frequency noise. The main device generating high-frequency sound was a system consisting of peripheral nozzles located around the main (base) nozzle. It was shown that sound irradiation has a significant effect on the aerodynamic and acoustic characteristics of subsonic turbulent jets.

Vestnik of Samara University. Natural Science Series. 2024;30(4):46-52
pages 46-52 views
Nonlinear equations of flexible plates deformations
Koifman K.G., Lychev S.A.
Abstract

Nonlinear equations of deformation of flexible plates are formulated in general nonorthogonal coordinates with taking into account incompatible local deformations. The following assumptions are used. 1. Displacements of the plate from the reference (self-stressed) shape are restricted by the kinematic hypotheses of Kirchhoff — Love. 2. Elementary volumes constituting the reference shape can be locally transformed into an unstressed state by means of a nondegenerate linear transformation (hypothesis of local discharging). 3. Transformations inverse to local unloading, referred to as implants, can be found from the solution of the evolutionary problem simulating the successive deposition of infinitely thin layers on the front boundary surface of the plate. Geometric spaces of affine connection that model the global stress-free reference shape are constructed. The following special cases are considered: Weitzenböck space (with non-zero torsion), Riemann space (with non-zero curvature) and Weyl space (with non-zero non-metricity).

Vestnik of Samara University. Natural Science Series. 2024;30(4):53-83
pages 53-83 views
Experimental assessment of determining the average size of speckles
Sergeev R.N.
Abstract

The paper proposes a method for estimating the average speckle size using experimentally recorded images of speckle fields on a CMOS matrix. This method can be useful when used in speckle interferometry methods when determining their metrological parameters.

Vestnik of Samara University. Natural Science Series. 2024;30(4):84-91
pages 84-91 views

Mathematical Methods in Natural Sciences

Numerical simulation of the oil pipeline temperature field for the thermal method of measuring the thickness of paraffin deposits taken into account of oil movement
Artur M.K., Ryzhova E.A., Yaroslavkina E.E.
Abstract

The article provides an analysis of the problems of precipitation of asphaltresin-paraffin deposits on the inner surface of the walls pipelines. The problem of numerical modeling of the temperature field of the heated oil pipeline in the ANSYS software product is considered. The process of heating and cooling the pipeline at different sediment thicknesses and oil velocities is investigated. A two-dimensional numerical model of the oil pipeline has been developed, which allows studying the behavior of its temperature field during heating and cooling. The research developed in the article helps to reduce the cost of maintaining oil pipelines.

Vestnik of Samara University. Natural Science Series. 2024;30(4):92-100
pages 92-100 views
Non-isothermal mathematical model of blocking tecnogenic fractures
Kasperovich A.M., Shevelev A.P., Gilmanov A.Y.
Abstract

Nowadays, large oil fields have moved to the stage of declining production, to maintain reservoir pressure, it is necessary to apply flooding technologies. To maintain the previous rates of oil production, it is necessary to force selections by increasing the value of downhole pressure on the injection wells. However, the risks of exceeding the fracturing pressure are increasing, which can lead to the formation of technogenic fractures. An intensive increase in the fracture can lead to an increase in the risks of premature water reaching through it into the drainage zone of the producing wells, which will lead to an increase in the value of the water oil ratio. The analysis of current numerical mathematical models of colmatation of technogenic fracture has shown the status of determining the volume of leaks of the colmatation agent beyond the fracture, considering changes in the temperature field at the bottom of the injection well. This problem is relevant, since special research complexes have been conducted at several oil and gas fields to determine the growth of technogenic fractures that arose because of excess fracturing pressure and fell into the drainage zone of producing wells. A change in the temperature field of the reservoir will allow direct changes in the viscosity of the injected colmatation agent, as well as determine the amount of leakage of the agent beyond the limits of the technogenic fractures. The article describes the construction of a non-isothermal physico-mathematical model of injection of a suspension system (water-reagent) into the reservoir, considering changes in the temperature field of the reservoir, the volume of reagent leaks beyond the limits of the technogenic fracture, considered for the first time. The aim of the work is to establish the dependences of the leakage volume of the colmatation agent, the critical time of filling the fracture from changes in the temperature field at the bottom of the injection well. A nonisothermal reservoir simulation model has been constructed showing the stages of initiation of a technogenic fracture with its subsequent colmation. The distribution of the concentration of the colmatation reagent both in the fracture and outside it, depending on the change in the temperature field at the bottom of the well, is obtained. It is determined that the volume of reagent leaks decreases if changes in the temperature field at the bottom of the injection well are considered with identical well operation parameters and geological and physical characteristics of the formation.

Vestnik of Samara University. Natural Science Series. 2024;30(4):101-115
pages 101-115 views

Physics

Associated production of J/ψ and direct photon in the parton Reggeization approach
Alimov L.E., Karpishkov A.V., Saleev V.A.
Abstract

We study the associated J/ψ and direct photon production in the high energy factorization, as it is formulated in the parton Reggeization approach, using two different models for the hadronization of a heavy quark-antiquark pair into a heavy quarkonium, namely the non-relativistic quantum chromodynamics (NRQCD) and the improved color evaporation model (ICEM). We find essential differences in predictions for cross section and transverse momenta spectra obtained using the NRQCD and the ICEM, which can be used for the discrimination between these models. Our prediction for cross sections of the associated J/ψ and direct photon production at the LHC energies slightly overestimate the results early obtained in the next-to-leading order (NLO) calculation in the collinear parton model (CPM). We predict different two-particle correlation spectra in the associated J/ψ and direct photon production which may be interesting for an experimental study

Vestnik of Samara University. Natural Science Series. 2024;30(4):116-132
pages 116-132 views
Production of J/ψ within the Soft Gluon Resummation Approach and Nonrelativistic QCD
Saleev V.A., Shilyaev K.K.
Abstract

In our study we analyse prompt J/ψ production in proton-proton collisions within the Soft Gluon Resummation approach, collinear parton model and nonrelativistic QCD. We extract a set of long-distance matrix elements for octet color states from experimental data at √s = 200 GeV. We use the InEW scheme for matching cross section and description of J/ψ production in a domain of intermediate transverse momenta. We also provide prediction for J/ψ production using fitted matrix elements at the kinematics of SPD NICA.

Vestnik of Samara University. Natural Science Series. 2024;30(4):133-146
pages 133-146 views

Informatics and Computer Science

Features of using Markov decision-making processes when modeling attacks on artificial intelligence systems
Vetrov I.A., Podtopelny V.V.
Abstract

In this paper, we study the features of modeling attacks on artificial intelligence systems. Markov decision-making processes are used in the construction of the model. A multilevel approach to the interpretation of system states is proposed, which includes several stages of detailing the states. This approach is based on the MITRE ATLAS methodology and the FSTEC Threat Assessment Methodology. When forming the vector, the specifics of the intruder model are taken into account, and two main modeling modes are considered: on-time and off-time. The procedure for the formation of awards at the abstract level (without specifying the actions of the attacker) of building a model is described.

Vestnik of Samara University. Natural Science Series. 2024;30(4):147-160
pages 147-160 views