SIBERIAN JOURNAL OF PHYSICS. Scientific Journal. 2019. V14, i 2

High-Energy and Accelerator Physics, Physics of High-Temperature Plasma

Domarov E. V., Vorobyov D. S., Golkovsky M. G., Golubenko Yu. I., Korchagin A. I., Kuksanov N. K., Lavrukhin A. V., Nemytov P. I., Salimov R. A., Semenov A. V., Sorokin A. V., Fadeev S. N., Chakin I. K., Cherepkov V. G. Research of Parameters of the Powerful Electron Beam of Industrial Accelerator ELV

This article deals the factors affecting the diameter and angle of divergence of the electron beam at the exit from the accelerator tube of an industrial ELV series accelerator. Measurements of the parameters of a high-power electron beam were carried out up to a power of 100 kW. On the basis of the data obtained, a new type of gas-dynamic extraction device was designed and pre-tested, which can efficiently output a focused electron beam to the atmosphere.

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Physics of a Fluid, Neutral and Ionized Gases

Kozlov V. V., Grek G. R., Katasonov M. M., Litvinenko M. V., Litvinenko Yu. А., Tambovtsev A. S., Shmakov A. G. Features of the Round Hydrogen Microjet Combustion in a Coaxial Air Jet

Results of experimental studies of features of the round hydrogen microjet combustion in a coaxial air jet are presented in this work. It is shown that the combustion scenario is connected with existence of the «bottleneck flame region». This fact correlates with the similar scenarios of the diffusion hydrogen microjet combustion at subsonic efflux velocity investigated by us earlier. It is revealed that the spherical shape of the “bottleneck flame region” is transformed to a cylindrical shape. It is found that the round hydrogen microjet combustion in a coaxial air jet at supersonic efflux velocity is accompanied by existence of supersonic cells both in a hydrogen microjet and in a wake of coaxial air jet. Round hydrogen microjet supersonic combustion in a coaxial air jet is connected with a flame separation from a nozzle exit.

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Kozlov V. V., Grek G. R., Litvinenko M. V., Litvinenko Yu. А., Tambovtsev A. S., Shmakov A. G. Features of the Round Hydrogen Microjet Combustion in a Coaxial Jet of the Air and Nanopouder Mixture

Results of the experimental studies of a round hydrogen microjet combustion in a coaxinal jet of air and SiO₂ nanopouder mixture efflux from a slot-hole (multinozzle) coaxial nozzle at subsonic and supersonic efflux velocity are presented. It is shown that scenarios of a hydrogen microjet combustion in a coaxinal jet of air and nanopouder mix-ture are similar to scenarios of diffusion combustion of a hydrogen microjet at subsonic and supersonic efflux veloci-ty. Existence of “bottleneck flame region” is revealed at subsonic and a flame separation from a nozzle exit at super-sonic efflux velocity. It is found that with efflux velocity growth of jets it is possible to observe intensification of the luminescence of the flame at the boundary between the jet of hydrogen and air / nanopowder mixture and existence of «bottleneck flame region» as in a laminar coaxial jet and in a flame of a hydrogen microjet combustion. On the other hand, it is possible to observe actually disappearance of the «bottleneck flame region» at approach to transonic efflux velocity.

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Kocharin V. L., Yatskikh A. A., Kosinov A. D., Yermolaev Yu. G., Semionov N. V. Experimental Study of the Weak Shock Wave Action on the Boundary Layer of a Plate at the Mach Number 2.5

Experimental study of the effect of a weak shock wave from the protuberance of two-dimensional roughness installed on the side wall of the test section of the wind tunnel on the supersonic boundary layer of the blunted flat plate at the Mach number 2.5 was carried out. The measurements were performed by a constant temperature hot-wire anemometer in the region of stream wise vortices generated by the shock wave from the protuberance during interaction with the flow in the vicinity of the leading edge of the model. The spectral and statistical analyses of the measured disturbances in the boundary layer were carried out. The amplitude-frequency spectra of mass flow pulsations and statistical diagrams of the measured disturbances in the supersonic part of the boundary layer were obtained.

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Gubanov D. A., Kundasev S. G., Trubitsyna L. P. Influence of Different Configurations of Microjet Injection on Structure and Acoustic Radiation of Supersonic Jet

The work is devoted to experimental study of the structure and acoustic radiation of a supersonic underexpanded jet Ma = 1, Npr = 5 with the presence of vortexgenerators in the form of small-sized jets injections. Ten different configu rations were tested, in which following the gas-dynamic and geometrical parameters of the microjets were changed one by one: microjets pressure, the injection distance from the main nozzle section, azimuthal, tangential, and axial angles of micronozzles inclination. The flow visualization, azimuthal Pitot pressure profiles and characteristics of jet noise in the far field were obtained. It has been revealed that the injection of microjets in general leads to an increase in the jet long-range and a decrease in its mixing. The advantageous parameters of the microjets injection for reducing the jet acoustic emission are the injection point vicinity to the main nozzle section, micronozzles inclination to main jet axis and the small tangential angle of micronozzles. The micronozzles quantity effect is non-linearly in relation to the structure and the jet noise. The average pressure measuring distribution near artificial longitudinal vortices in a jet stream cannot predict the characteristics of its mixing and acoustic radiation.

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Afanasev L. V., Yatskih A. A., Kosinov A. D., Yermolaev Yu. G., Semionov N. V., Minin O. P., Shevelkov S. G. A Study of the Pulsations of Flow in the Settling Chamber and Their Relationship with the Pulsations of the Supersonic Flow

Experimental study of the influence of flow pulsation in settling chamber on the supersonic free stream disturbances was carried out. Data on the pulsations in the settling chamber and the efficiency of deturbulization system as well as the correlation of pulsations of the flow of settling chamber and flow pulsations in test section of T-325 supersonic wind tunnel of ITAM SB RAS were obtained.

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Solid-State and Semiconductor Physics, Physics of Nanostructures

Kuznetsov S. A., Nikolaev N. А., Trashkeev S. I., Lazorskiy P. A., Arzhannikov A. V. Application of the Concept of Ultra-Thin Resonant Absorbers for Controlling Millimeter-Wave Radiation by Means of Liquid Crystals

A consideration of ultra-thin resonant absorbers of electromagnetic radiation utilizing high-impedance metasurfaces is carried out in terms of an equivalent circuit theory. By incorporating a thin layer of tunable dielectric into such structures it is feasible to manipulate the radiation amplitude and phase under the condition of a small thickness of the dielectric layer in comparison with the radiation wavelength. As such a dielectric, the nematic liquid crystal 5CB with a thickness of 80 um was chosen, and a 5CB-based prototype of an absorbing metastructure of the reflective type optimized for operation in the vicinity of a frequency of 140 GHz was fabricated and experimentally studied. Testing the structure revealed good agreement between the calculated and experimental reflection spectra. The results of this work can be useful for modeling and developing quasi-optical and integrated active devices of terahertz photonics.

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Geshev P. I. Calculation of Giant Combination Light Scattering on a Dipole Located between Metallic Nanoparticle and Metallic Nanofilm on Substrat (TERS Theory)

A metallic nanoparticle (NP) located near the film acts as a nanoantenna. Surface plasmons, excited by light in a particle and in a film, transform the electromagnetic field, confine it and strongly amplify it in the gap between the particle and the film. The enhancement of the field depends on many factors: the size and shape of NP, the permeability of all materials, the wavelength of light, the thickness of the film, the angle of the light beam and very much from the gap between the particle and the film. The amplification of the field in a narrow gap (~ 1 nm) can be 1000 or more and the enhancement of Raman radiation can reach enormous values of ~ 10¹⁰–10¹¹.

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Instructions to Contributors

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