SIBERIAN JOURNAL OF PHYSICS. Scientific Journal. 2017. V12, i 3

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

Bondar A. E., Buzulutskov A. F., Dolgov A. D., Nosov V. V., Oleynikov V. P., Sokolov A. V., Frolov E. A., Shemyakina E. O., Shekhtman L. I. Study of Proportional Electrolyuminescence
in Two-Phase Argon

In this work proportional electroluminescence (EL) in gaseous argon with a minor (9 ppm) admixture of nitrogen has been studied. The effect of enhancement of the EL yield and the presence of a UV component in proportional electroluminescence in two-phase Ar were confirmed. On the other hand, the effect of EL yield enhancement can not be explained by a UV contribution. The results obtained are relevant in the field of noble-gas liquid detectors for dark matter search and low-energy neutrino experiments.

5

Bondar A. E., Buzulutskov A. F., Grishnyaev E. S., Dolgov A. D., Nosov V. V., Oleynikov V. P., Polosatkin S. V., Sokolov A. V., Shemyakina E. O., Shekhtman L. I. Measurement of the Ionization Yields of Nuclear Recoils in Liquid Argon Using a Two-Phase Detector with Optical Readout

Measurement of the ionization yields of nuclear recoils is related to the energy calibration of dark matter detectors and low-energy neutrinos. In the present work, the ionization yields of nuclear recoils in liquid argon have been measured using the neutron generator and the two-phase detector with optical readout. The ionization yields in liquid argon amounted to 5,9 ± 0,8 and 7,4 ± 1 e–/keV at electric fields of 0,56 and 0,62 kV/cm respectively. The characteristic dependences of the ionization yield on energy and electric field were determined, while comparing the results obtained in other experiments.

16

Physics of a Fluid, Neutral and Ionized Gases

КKaprilevskaya V. S., Tolkachev S. N., Kozlov V. V. Influence of Two-Dimensional Roughness on the Swept Wing Boundary Layer Structure in the Favorable Pressure Gradient Region

The paper presents the results of an investigation of the processes occurring in the flow around a two-dimensional roughness located at the leading edge of the swept wing. Patterns of the distribution
of the boundary layer stationary disturbance behind a two-dimensional roughness in the height range from 0 to 1.04 mm are obtained in the presence of localized cylindrical roughness element.
The multiplication of longitudinal structures is observed, which is amplified by the injection of an acoustic field with a frequency of 500 Hz.

24

Yermolaev Yu. G., Kosinov A. D., Kosorygin V. S., Semionov N. V., Semenov A. N., Smorodsky B. V., Yatskikh A. A. Influence of Small Angles of Attacks on the Laminar- Turbulent Transition on a Swept Wing at Mach Number M = 2

Experimental studies on the effect of small angles of attack on the laminar-turbulent transition of swept-wing supersonic boundary layer have been performed. In the experiments, a 3 % symmetrical
swept-wing model with a lenticular profile and a swept angle of 45° was used. The position of the transition was determined using a hot-wire anemometer. The growth of pulsations was measured.
The positions of the laminar-turbulent transition were determined. The amplitude-frequency pulsation spectra in the supersonic boundary layer were obtained for certain values of the angle of attack.
In the framework of the linear theory of stability, calculations on the effect of small angles of attack on the development of perturbations were provided. A comparison of the experimental Reynolds
number of the transition for different values of the angle of attack of the model and the calculated dependences obtained for different values of the N-factor was made. The results of calculations on
the linear stability theory are in good qualitative agreement with the experimental data.

35

Yatskih A. A., Semenov A. N., Yermolaev Yu. G., Kosinov A. D., Semionov N. V. Influence of Pulsed Discharge Parameters on Pulsations of Flat-Plate Supersonic Boundary Layer

The results of experimental study of the influence of the parameters of a pulsed discharge on the localized pulsations in the flat-plate supersonic boundary layer are presented. The experiments were
performed in a supersonic low-turbulent wind tunnel T-325 of ITAM SB RAS at Mach number M = 2. It is experimentally established that the duration of the discharge affects on the spatial scales
and the amplitude of the generated perturbations. Studies of the evolution downstream of localized perturbations of different amplitudes were carried out. The propagation velocities of controlled pulsations in the boundary layer were estimated. Linear and nonlinear regimes of evolution of localized perturbations were found.

41

Mironov D. S., Lebiga V. A., Miau J. J., Pak A. Yu., Zinoviev V. N. Application of Hilbert- Huang Transform for Analyzing of Fluctuations behind Circular Cylinder

One of the most important goals of experimental gas dynamics is to study formation and evolution of fluctuations generated by flow over some obstacles. Such fluctuations are mostly nonstationary. To analyze such experimental data time-frequency techniques are required in order to provide not only mean value of frequencies and corresponding amplitudes in whole signal but also temporal variation of frequency and amplitude of specific process. Hilbert-Huang transform is one of such techniques. Abilities of the method are presented in this paper. Fluctuations of velocity behind a circular cylinder are analyzed at sub-critical Reynolds number.

49

Kozlov V. V., Grek G. R., Kozlov G. V., Litvinenko Yu. А., Shmakov A. G. Experimental Study of the Diffusion Combustion of a Round Hydrogen Microjet at Its Ignition Far from the Nozzle Exit

A scenario of subsonic diffusion combustion of the round hydrogen microjet at its ignition far from the nozzle exit is proposed. Stabilization of supersonic diffusion combustion of a hydrogen microjet at its ignition far from the nozzle exit due to the absence of connection between flame and micronozzle exit, i.e. absence of the nozzle heating is found. It is shown that absence of the nozzle heating because of the flame lifted leads to the supersonic mechanism of the hydrogen microjet combustion characterized by disappearance of the «bottleneck flame region», flame separation and supersonic cells occurrence. It is found that one of the stabilizing supersonic combustion factors is existence of the supersonic cells both in jet, and flame.

60

Vikhorev V. V., Grek G. R., Kozlov V. V., Litvinenko M. V., Litvinenko Yu. А., Shmakov A. G. Diffusion Combustion of the Round Hydrogen Jet Efflux from Curved Channel with the Dean’s Vortices

Results of the experimental studies of the round hydrogen jet efflux from curved micronozzle with Dean's vortices are presented in this work. Existence of the «bottleneck flame region» is revealed,
as well as in situations of the hydrogen microjet combustion efflux from linear round and plane micronozzles. It is shown that interaction of the Kelvin – Helmholtz ring vortices with Dean’s vortices leads to distortion of the «bottleneck flame region» and curvature of front of the gas density gradient between laminar combustion of hydrogen in «bottleneck flame region» and its turbulent combustion. It is found that with growth of the microjet efflux velocity it is possible to observe already and distortion of a turbulent flame region in presence of the «bottleneck flame region». It is shown that position of this distortion is placed in region of the velocity maximum in mean velocity profile at the nozzle exit and obviously this distortion is connected with influence of the Dean’s and ring vortices. Further growth of the microjet efflux velocity leads to «bottleneck flame region» disappearance and flame detachment from the nozzle exit, but distortion of the region of a turbulent flame remains. Disappearance of the «bottleneck flame region» and a flame separation from the nozzle exit indicate transition of subsonic diffusion combustion of a hydrogen microjet with Dean's vortices to supersonic diffusion combustion and possible emergence of supersonic cells.

72

Litvinenko Yu. A. Stability of Subsonic Macro- and Microjet Flows and Microjet Combustion (Review)

In this review series of works of experimental study of the outflow of gas jets into air are presented. Air, propane, hydrogen were applied as gas of jet. Investigations were carried out for different sizes of round nozzles (from 23 to 0.2 mm) and flat nozzles (from 3000·1.5 to 0.7·0.1 mm), for different velocities in the range of Re numbers for macro-jet ~ 3000–5000, and for micro-jet Re ~100–300. Based on the results of the research, the mechanisms of the growth of perturbations in a round and flat macro-jet are determined, and also methods for reduction of hydrodynamic perturbations in jets. The properties of micro jets in the diffusion combustion of various gases are shown, including acoustic excitation of the jet. The features of the diffusion combustion of hydrogen with formation of so-called «constriction» of the flame and two combustion zones are shown.

83

Prokhorov E. S. Exciting a Shock Wave by Detonation Refraction at the Diffuse Interface between Reacting and Inert Gases

The non-stationary problem of exciting a plane shock wave by gas detonation in a tube is numerically solved. The case when the field of mixing the reacting and inert gases located at the closed end of the tube has finite sizes is considered. The influence of mixing field width on the intensity and law of decay of excited shock waves is studied. Ignoring energy losses, the problem solution is determined by one dimensionless parameter equal to the ratio of gas mixture volume in the field of mixing to the volume of reacting gas located in the tube before the detonation is initiated. By varying this parameter from 0 to 2, the maximal value for the Mach number of the shock wave in the inert gas (air) decreases by only 20 %. It is established that the law of decrease of the shock wave front velocity can be approximately described by the dependence corresponding to the conclusions made from the theory of point explosion for the case of plane adiabatic gas motions.

100

Solid-State and Semiconductor Physics, Physics of Nanostructures

Borisov G. M., Fol’dort V. G., Kovalyov A. A., Ledovskikh D. V., Rubtsova N. N. Reflectivity Kinetics of the Fast Semiconductor Mirror

The shape of kinetic curves for reflectivity of the fast semiconductor A3B5 mirror with saturable absorption is investigated by single-frequency pump-probe technique centered at 1 035 nm with the pulse duration of 130 fs and the repetition rate of 70 MHz in the exciting radiation intensities region of 0.16–5.44 GW/cm2. Modeling and comparison with the experiment is accomplished. It is shown that the signal increase is determined by the femtosecond radiation pulse front and by the excitons lifetime; the short peak at the beginning of the curve reflects the process of excitons ionization. The charge free carriers contribution appears after quasi-equilibrium installation time of about 1 ps, and it disappears with the characteristic electron-hole recombination time of about 10 ps, which controls the mirror’s performance.

107

Brusentseva T. A., Fomin V. M. Modification of Epoxy Binder for Glass and Basalt Rebar. The Results of Mechanical Tests

The paper presents the results of experimental studies on the modification of the epoxy binder LE-828 for the manufacture of glass and basalt rebar. The nano-size silica powder is used as a filler. The filler mass content ranged from 0 to 2 %. The influence of air bubbles on the mechanical characteristics of epoxy composite was evaluated. It is shown that the nano-disperse filler introduced in the binder leads to the increasing breaking stress and tensile strength by 33 and 34 %, respectively; the failure strain increased by 39 % at the filler mass content of 0.6 %.

114

Our Contributors

120

Instructions to Contributors

123

Up to main