2304-9782, 2618-8686, 2405-7223 14 3 2021 1-187

RAR RUS 8-20 Herzen State Pedagogical University of Russia Gorokhovatskiy Yuriy yurig@fromru.com Herzen State Pedagogical University of Russia Temnov Dmitry tde@herzen.spb.ru Herzen State Pedagogical University of Russia Shabanova Natalya natashshabanov@yandex.ru Joint Institute for Nuclear Research Rossouw Arnoux arnoux.rossouw@gmail.com Thermoactivated current spectroscopy of polyethylene terephthalate films irradiated by heavy xenon ions The paper analyzes the electret state of polyethylene terephthalate (PET) films irradiated on the IC-100 cyclotron (JINR LAR) using thermostimulated spectroscopy methods. Thermally stimulated discharge currents (thermally stimulated depolarization) of PET film samples obtained at different technological stages of track membrane manufacturing are studied. The results of the analysis of thermally stimulated depolarization currents indicate a significant change in the spectra of the energy states of the electric charge accumulated during the polarization of PET films, during irradiation with accelerated heavy Xe ions, ultraviolet treatment, and alkaline etching of latent tracks. The parameters of relaxation processes (activation energy and effective frequency factor) occurring in track membranes are calculated using the Eyring method. A significant change in the energy state spectra of the electric charge accumulated during the polarization of PET films as a result of ion-track processes in them indicates the possibility of creating an electret state in PET films and track membranes irradiated with heavy ions on their basis. 10.18721/JPM.14301 53.08 electret track membrane polyethylene terephthalate thermal-stimulated discharge current Eyring method https://physmath.spbstu.ru/article/2021.53.1/ 01_8-20_14(3)2021.pdf

RAR RUS 21-35 E-5484-2014 56020596900 Peter the Great St. Petersburg Polytechnic University Smirnov Evgeny aero@phmf.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0000-0002-3972-9259 Northern Water Problems Institute of Karelian Research Centre of RAS Smirnov Sergei sergeysmirnov92@mail.ru Peter the Great St. Petersburg Polytechnic University Abramov Alexei abramov@runnet.ru Peter the Great St. Petersburg Polytechnic University Galaev Sergey galaev@spbstu.ru Turbulent mixed convection within rapidly rotating heated annular cavities with an axial throughflow The results of eddy-resolving numerical simulation of a turbulent mixed convection in a system of three identical, rapidly rotating annular cavities are presented. The cavities are heated from the side of the disk surfaces and from the periphery (the same distribution of the surface temperature is set for all the cavities), and heat removal proceeds by an axial air throughflow in the narrow channel, annular within the cavity system. The computations based on the Implicit LES method have been carried out in view of the conditions close to the experiments known from the literature for a single cavity; the rotational Reynolds number was 200,000, the grid dimension was 17 million cells. The complex multiscale flow structure and the influence of the input aerodynamic and thermal conditions, which are not identical for the cavities included in the system, on the local heat transfer from disk surfaces are discussed. 10.18721/JPM.14302 536.25, 532.517 mixed convection rapidly rotating annular cavity axial throughflow global circulation https://physmath.spbstu.ru/article/2021.53.2/ 02_21-35_14(3)2021.pdf

RAR RUS 36-48 Peter the Great St. Petersburg Polytechnic University Bulovich Sergei bulovic@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Numerical simulation of thermoacoustic gas oscillations in a pipe with toroidal heat exchange elements The paper simulates the modes of a gas flow in a pipe closed at one end and open to the atmosphere at the other end; for this purpose, a numerical solution of the system of Navier – Stokes equations in a two-dimensional axisymmetric formulation has been used. The excitation of oscillations of gas-dynamic functions is caused by the temperature gradient in the pipe section resulting from the contact of the gas with differently heated toroidal elements inside the pipe, their temperature being maintained constant. When the specified gradient reaches the threshold value, a stable thermoacoustic oscillation of the gas column is observed in the pipe. The time dependences of the pressure and the axial component of the gas velocity, as well as the heat flows in the heat exchange unit of the resonator, were calculated. The obtained results were in good agreement with the experimental data. 10.18721/JPM.14303 621.486 thermoacoustics Sondhauss effect mathematical simulation numerical solution of Navier – Stokes equations https://physmath.spbstu.ru/article/2021.53.3/ 03_36-48_14(3)2021.pdf

RAR RUS 49-62 Peter the Great St. Petersburg Polytechnic University Borisenko Vladislav vladborisenko1995@gmail.com Peter the Great St. Petersburg Polytechnic University Semenov Artem semenov.artem@googlemail.com Dresden University of Technology Wallmersperger Thomas servicecenter.studium@tu-dresden.de

Germany

An influence analysis of creep and plasticity characteristics on the spark plasma sintering process In the paper, the spark plasma sintering (SPS) process for metal particles has been simulated based on experimental data and using the finite element method in the thermo-electro-mechanical formulation with taking into account the temperature influence on parameters of materials (nickel and copper). A comparison of obtained results with experimental data made it possible to create a computational model of the SPS process, the model being convenient to evaluate the influence of creep and plasticity parameters on the size of the interparticle neck forming in SPS. It was found that the creep effect significantly dominated over the plasticity influence on the process of forming the sintering neck at high temperatures. In this case, the variation of creep parameters in simulation also actively affects the formation of the neck. 10.18721/JPM.14304 004.94 spark plasma sintering metal finite-element modelling plasticity creep coupled fields https://physmath.spbstu.ru/article/2021.53.4/ 04_49-62_14(3)2021.pdf

RAR RUS 63-78 Peter the Great St. Petersburg Polytechnic University Dudoladov Savelii sava2312@yandex.ru Peter the Great St. Petersburg Polytechnic University Larionov Nikolay larionov.nickolay@gmail.com The condition for application of the Crocco integral in the mathematical description of a laser welding plasma plume Based on the theoretical approach developed in the article by G.A. Turichin et al. (High Temperature. 2006. Vol. 44. No. 5. Pp. 647–655), the characteristics of the plasma plume forming in the keyhole laser welding have been investigated. A condition corresponding to the existence of the Crocco integral was defined, making it possible to simplify the system of gas dynamics equations and obtain analytical solutions for a plasma plume in the form of a classical submerged jet. These solutions were analyzed for a wide range of metal vapor velocities and temperatures at the keyhole top. For some of the selected values, an agreement with the numerical calculations of other authors was found. 10.18721/JPM.14305 533.1; 621.791 gas dynamics equations plasma plume laser welding shear layer submerged jet https://physmath.spbstu.ru/article/2021.53.5/ 05_63-78_14(3)2021.pdf

RAR RUS 79-93 Voronezh State University Kutsova Daria potanina.ds@gmail.com Voronezh State University Bogatikov Evgenii evbogatikov@yandex.ru Voronezh State University Shebanov Alexandr anshebanov@hotmail.com Voronezh State University Bormontov Evgenii me144@phys.vsu.ru A comparison of potential functions for molecular dynamic simulation of methane sorption in the silicalite In order to make the best choice, two types of a force field have been studied to access a possibility of application of one of them to simulation of adsorption and transport processes in the silicalite (synthetic zeolite)-methane system. To accomplish this, the molecular dynamic technique implemented in the LAMMPS package was used. Priority criteria of the choice were retention of the structure completeness during long simulation runs, the system’s stability, the possibility of simulation of a separate good-sized zeolite cluster without using periodic boundary conditions for multiplying zeolite’s lattice in space. For the force-field, which met these requirements, some structural, thermodynamic and transport characteristics of the system were calculated. Radial and angular distribution functions for different atom pairs and triplets were obtained for both the pure zeolite and the silicalite-methane system. A good agreement of all obtained characteristics with literature data of numerical and natural experiments was achieved. 10.18721/JPM.14306 538.913 silicalite ZSM-5 zeolite methane molecular dynamic sorption potential function https://physmath.spbstu.ru/article/2021.53.6/ 06_79-93_14(3)2021.pdf

RAR RUS 94-111 Peter the Great St. Petersburg Polytechnic University Stepasheva Ekaterina momoirin@yandex.ru Peter the Great St. Petersburg Polytechnic University Zasimova Marina zasimova_ma@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ivanov Nikolay ivanov_ng@spbstu.ru Thermal manikin shape influence on airflow and heat transfer in the model room with displacement ventilation The paper presents the results of numerical modeling of turbulent flow and heat transfer in the model room with displacement ventilation. The goal of the study is to assess the shape influence of the thermal manikin placed in the room on the computed airflow structure. Three manikin shapes have been considered: a detailed one (close to a human shape) and ones simplified partially and completely. The problem formulation was close to the test conditions of P.V. Nielsen et al. (2003). The RANS approach based on the standard k-ε turbulence model was applied. The study revealed solution sensitivity to the dimension and topology of the mesh used, as well as the solution dependence on the uncertainty of the inlet velocity distribution. The calculated results were shown to agree generally with the experimental data. The simplification of the manikin shape had a significant impact on the local parameter prediction accuracy. 10.18721/JPM.14307 532.517 ventilation thermal manikin turbulent airflow and heat transfer natural convection https://physmath.spbstu.ru/article/2021.53.7/ 07_94-111_14(3)2021.pdf

RAR RUS 112-121 Peter the Great St. Petersburg Polytechnic University Petrov Vladimir petrov@physics.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0000-0002-2519-2577 Peter the Great St. Petersburg Polytechnic University Gabdullin Pavel gabdullin_pg@spbstu.ru Peter the Great St. Petersburg Polytechnic University Pavlov Alexander a.pavlov@physics.spbstu.ru Peter the Great St. Petersburg Polytechnic University Ustinov Alexander ustinov@physics.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Paul Scherrer Institute Strocov Vladimir vladimir.strocov@psi.ch

Switzerland

Paul Scherrer Institute Dil Jan Hugo jan-hugo.dil@psi.ch

Switzerland

Projecting classical Mott polarimeter In this paper we describe a new spin detector designed and manufactured at SPbPU. This device makes it possible to analyze the polarization of the secondary electron flux conserving the information about the electrons' spatial distribution. The main stages of development, construction and testing the detector are discussed in details. As a result, the possibility of implementing such devices has been proved in principle. At the same time, both high spatial resolution of this device and its efficiency were demonstrated. Combining such detectors with hemispherical energy analyzers will make it possible to obtain spin-resolved dispersion images of the structure under study. 10.18721/JPM.14308 53.07, 538.9 Mott detector spin electron spectroscopy secondary electron polarization https://physmath.spbstu.ru/article/2021.53.8/ 08_112-121_14(3)2021.pdf

RAR RUS 122-132 Peter the Great St. Petersburg Polytechnic University Dyubo Dmitry doobinator@rambler.ru Peter the Great St. Petersburg Polytechnic University Makarov Sergey makarov@cee.spbstu.ru Military Space Academy named after A.F. Mozhaysky Kuleshov Yuri vka@mil.ru Military Space Academy named after A.F. Mozhaysky Goncharov Pavel vka@mil.ru Military Space Academy named after A.F. Mozhaysky Shunevich Nikolay vka@mil.ru Military Space Academy named after A.F. Mozhaysky Martynov Viktor vka@mil.ru Peter the Great St. Petersburg Polytechnic University Tsybin Oleg otsybin@rphf.spbstu.ru A model of an ion plasma electrically powered spacecraft propulsion with a remote monitoring and a control system This paper continues the publication cycle on developing the ion plasma electrically powered spacecraft propulsion (EPSP) of the spacecraft. For monitoring and control of the EPSP operation, a feedback system based on a signal proportional to the EPSP plasma radiation intensity has been proposed to be used. It was assumed that the radiation intensity in the ultraviolet, visible and infrared ranges being proportional to the instantaneous thrust value of the EPSP. Accordingly, the introduction of a signal from the radiation registration detector into the feedback loop should allow to create an onboard closed system for monitoring and control of the EPSP operation. A photodetector based on a dynamic pin-diode integrator was considered for use in this system. 10.18721/JPM.14309 621.455.4; 621.455.34 ion plasma thruster acceleration neutralization plasma radiation photodetector automatic control https://physmath.spbstu.ru/article/2021.53.9/ 09_122-132_14(3)2021.pdf

RAR RUS 133-145 Kozhevnikov Vadim vadim.kozhevnikov@gmail.com 7006335646 Peter the Great St. Petersburg Polytechnic University Privalov Vadim kafedra@physics.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

AAD-9657-2019 57197390995 Peter the Great St. Petersburg Polytechnic University Fotiadi Alexander fotiadi@rphf.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

A new approach to the assessment of the output power for a helium-neon gas laser with different cross-sectional geometry of the active element The proposed study continues a series of articles devoted to design methods for the key energy parameters of a helium-neon (He-Ne) gas laser. An application of the previously proposed method for designing the emission power to lasers with the rectangle- and ellipse-shaped cross sections of active elements has been considered. An idea of effective mode volume was used, a calculation algorithm was presented, and a procedure reducing unwieldy calculations was put forward. Varying the parameter values made it possible to get a detailed picture of dependencies of the output laser energy on the geometrical parameters of objects under study. A comparison of the obtained results permitted to find optimal laser parameters for maximum output power. The calculation results of the radiation energy were established to agree well both with those of the laser gain for the given cross sections and those of the experimental data. 10.18721/JPM.14310 621.373.8 helium-neon laser laser power tube geometry rectangular and elliptical cross sections https://physmath.spbstu.ru/article/2021.53.10/ 10_133-145_14(3)2021.pdf

RAR RUS 146-157 Institute for Analytical Instrumentation of the Russian Academy of Sciences Manoilov Vladimir manoilov_vv@mail.ru Institute for Analytical Instrumentation of the Russian Academy of Sciences Novikov Lev novik38@mail.ru Institute for Analytical Instrumentation Kuzmin Alexey agqz55@rambler.ru Institute for Analytical Instrumentation Titov Yuriy titov.uriy@gmail.com Institute for Analytical Instrumentation of the Russian Academy of Sciences Zarutskiy Igor igorzv@yandex.ru An algorithm for processing mass spectrometric analysis data for initial diagnostics of diseases by exhaled gases An algorithm for processing mass spectra of gases exhaled by patients has been proposed in the paper. The mass spectra are recorded on the MS7-200 quadrupole mass spectrometer, with electronic ionization and with direct capillary injection of the sample. The algorithm is based on transforming an array of spectra (not less than 10) in the space of principal components. The probability of a disease is determined through the Euclidean distance of the patient's coordinates from the centroid. Testing of the algorithm was carried out on the data of mass spectra of gases exhaled by cancer patients. The proposed procedure has several advantages over traditional laboratory methods. The algorithm uses the multidimensional probability density of the distribution of the parameters of the exhaled gases of control groups and the patient being tested and allows to compile an overall picture of the patient's probable diseases in a short time. 10.18721/JPM.14311 543.51+ 681.2–5 diagnostics principal component analysis multivariate probability density multivariate data processing https://physmath.spbstu.ru/article/2021.53.11/ 11_146-157_14(3)2021.pdf

RAR RUS 158-167 Peter the Great St. Petersburg Polytechnic University Mitrankova Mariia mashalario@gmail.com Peter the Great St. Petersburg Polytechnic University Bannikov Egor bannikov.ev.21@gmail.com Peter the Great St. Petersburg Polytechnic University Berdnikov Alexander alexber@phmf.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru Peter the Great St. Petersburg Polytechnic University Dubov Alexander alexanderpolytech@mail.ru 0000-0002-3395-0454 Peter the Great St. Petersburg Polytechnic University Kotov Dmitry dmitriy.kotov@gmail.com Peter the Great St. Petersburg Polytechnic University Mitrankov Yuriy mitrankovy@gmail.com

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

An analysis of φ-meson production in the collisions of proton beams with aluminum and gold nuclei at energies of 200 GeV In the paper, φ-meson production in the relativistic collisions at energies of 200 GeV measured by the PHENIX experiment (RHIC) has been studied. Phi-mesons’ nuclear modification factors were calculated for the mentioned interactions under conditions identical to the experimental ones, using different theoretical models, the results being compared. The accounting for the formation phase of quark-gluon plasma (QGP) in simulation was established to agree well with experiment for the p + Au collisions and disagree for the p + Al ones. This result could indicate an insufficient size of the interaction system of the latter to form QGP at an energy of 200 GeV and the sufficiency of the created minimum conditions for its formation in the former interaction system. 10.18721/JPM.14312 539.12 quark-gluon plasma cold nuclear matter effect nuclear modification factor https://physmath.spbstu.ru/article/2021.53.12/ 12_158-167_14(3)2021.pdf

RAR RUS 168-184 Fedosin Sergey sergey.fedosin@gmail.com The relativistic uniform model: the metric of the covariant theory of gravitation inside a body In the paper, it has been established that the sum of stress-energy tensors of the electromagnetic and gravitational fields, the acceleration and the pressure ones inside a stationary uniform spherical body vanishes within the framework of relativistic uniform model. This fact significantly simplifies a solution of the equation for the metric in the covariant theory of gravitation (CTG). The metric tensor components inside the body were calculated, and then they were combined with those of external metric tensor on the body’s surface. The latter procedure also allowed us to exactly determine one of two unknown coefficients in the metric outside the body. The comparison between the CTG metric and the Reissner – Nordström one in general theory of relativity clearly demonstrated their difference caused by discrepancy between equations for the metric and a difference in formulations of the cosmological constant. 10.18721/JPM.14313 514.13:531.51 metric covariant theory of gravitation scalar curvature cosmological constant https://physmath.spbstu.ru/article/2021.53.13/ 13_168-184_14(3)2021.pdf