Physics of Field, Neutral and Ionized Gases |
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Alekseenko A. V., Yakimov S. A. Electrohydrodynamic Modeling for Calculation of Electric Mobility of Aerosol Particles Charged in Corona Discharge In this paper the mobility of aerosol particles under different parameters of the charger with corona discharge have been calculated, comparison with the experimentally measured mobility have been made. The model developed allows to evaluate the efficiency of existing chargers and optimize its parameters. |
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Skripkin S. G., Dremov S. V., Shtork S. I., Kabardin I. K. Experimental Investigation of Couple Precessing Vortex Ropes in a Hydraulic Vortex The work is devoted to the experimental study of the interaction of the precessing vortex pair in the hydrodynamic vortex chamber. Swirling flow was created by a 12 tangentially directed rectangular nozzles. Design swirl number was varied in the range 0 - 6.6 based on the geometry of the swirl device. The Reynolds number was varied in the range of 6 000 - 52 000. Preliminary visual experiments has been conducted with changing output boundary conditions for controlling parameters of the vortex structure. It was found that stable mode with a double precessing structure is realized at full open outlet. Setting of diaphragm on the outlet of vortex chamber allows us to suppress the precession motion and significantly stabilize the flow. Further experiments included the quantitative measurement of the velocity distributions carried out using a laser Doppler anemometry (LDA). |
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Skripkin S. G., Tsoy M. A., Shtork S. I., Kuibin P. A. Investigations of Pressure Pulsations in a Model of Draft Tube of Hydraulic Turbine Caused by Vortex Rings Current work is devoted to experimental investigations of behavior of precessing vortex rope in a draft tube model of hydraulic turbine. We used combination of stationary and freely rotating swirlers as a hydro turbine model. Such construction provides velocity distribution on the draft tube inlet close to distribution in natural hydraulic turbines operated at non-optimal conditions. The phenomenon of precessing vortex rope reconnection with further formation of vortex ring was founded in this experimental research using high-speed visualization technique. Synchronization of highspeed visualization and pressure measurements allowed us to relate pressure shock on the draft tube wall with vortex ring moving along wall. |
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Bedarev I. A., Temerbekov V. M., Fedorov A. V., Rylova K. V. Numerical Modeling of the Ignition Initiation in the Scramjet Combustion Chamber via Detonation The paper studies of the cellular detonation wave interaction with supersonic reacting flow in the scramjet combustion chamber. Comparing the flow fields for the details and the reduced chemical kinetics models is allowed verifying the acceptability of the proposed simplified kinetic scheme. The possibility of using pulsating detonation for the ignition intensification in the scramjet combustion chamber is shown. Calculation of the detonation wave interaction with nonpremixed hydrogenair mixture is made. The ability to influence on the hydrogen-air mixing process by means of detonation tube is detected. The effect of tube sizes to intensification of hydrogen air mixing in the flow at channel with a cavity is calculated. |
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Zamuraev V. P., Kalinina A. P. Creating of Stable Transonic Zone into Supersonic Flow in Axisymmetrical Channel by the Action of Jet and Energy Sources The effect of the jet flowing out from the gas generator through a narrow annular gap, on the shockwave structure of the flow in the axisymmetric channel of variable section is studied. The effect of the gap size is investigated. The possibility to control the shock-wave structure of supersonic flow in the channel and creating of transonic area using pulsed-periodic energy supply and jet is studied. |
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Lebiga V. A., Zinoviev V. N., Pak A. Yu., Zharov I. R. The Circular Gap Couette Flow Modeling The simulation of Couette flow inside the circular gap between coaxial cylinders is observed due to the difficulty of the experimental implementation of the equal plane one, especially for rarefied gas conditions and high Knudsen numbers. Geometry configuration of the experimental facility have been defined in order to minimize speed profile deviation inside the gap from linear shape, existing in case of laminar flow and preventing appearance of Taylor – Gertler vortexes with chosen flow parameters. The previous stage, that was conducted using the hot-wire anemometer in atmosphere pressure onditions has shown the efficiency of the facility and sufficient agreement of calibration data, received using considered calibration method and data of standard calibration approach when the model wind tunnel DISA is applied. |
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Arinstein E. A., Tokarev D. K. Mathematical Model of Liquid Flow through the Pipe of Curcular Cross-Section This article analyses the properties of homogeneous viscous liquid flow in the pipe with variable cross-section characterized by cylindrical symmetry. The analytical approach is proposed in order to determine the flow velocity profile in the pipe’s extremium cross-sections. The conditions when dead spaces emerge in neighborhood of the maximum cross-section are identified. The particular case of problem-solving allowing prime presentation is examined for the set of current line allowing prime presentation. |
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Solid-state and semiconductor physics, physics of nanostructures |
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Zobov K. V., Syzrantsev V. V., Bardakhanov S. P. Features of Particle Size Measurements in the Nanosilica Hydrosol by the Optical Methods The current level of study and application of nanoparticles raises the question of their classification. One of the main parameters in this case is the particle size. However, its measurement on such a small scale is a valuable problem as usual models are not correct. The article presents the results of measurements of the light attenuation in the hydrosols (dispersions of nanoparticles in water). The Rayleigh scattering theory was applied to the experimental data for obtaining the average size of nanoparticles with various specific surfaces. The obtained values were compared with the results of the transmission electron microscopy analysis and with the results of dynamic light scattering measurements. All of measurements variants presented the specified value of medium size. It could be caused by the mechanics characteristics, structure and other properties of nanoparticles related to the surface properties and their production process. The Rayleigh theory gave the undervalued particle size, and dynamic light scattering gave overvalued one in a comparison with the microscopy data. It is shown that the light transmission attenuation strongly depends from the particle size, only for particles bigger than 15 nm. For smaller particles the association was not found. There are two different particle size ranges for dynamic light scattering measurement of different produced particle. |
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High-energy and accelerator physics, physics of high-temperature plasma |
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Arzhannikov A. V., Timofeev I. V. Intense Beam-Plasma Interaction as a Source of Sub- Millimeter Radiation Results of experimental and theoretical studies on the spectral content and polarization of submillimeter radiation generated in a dense (10E14–10E15 cm–3) magnetized plasma by a high-power (~10E10 W) relativistic (~10E6 eV) electron beam are presented. The spectral and polarization characteristics of electromagnetic waves emitted from the plasma are analyzed in the frequency band 0.1– 0.5 THz) corresponding to the vicinity of the plasma frequency and its second harmonic. The observed radiation fluxes escaping from a beam-plasma system in the transverse and longitudinal direction agree with our theoretical insights based on the dominant excitation of upper-hybrid waves and their further conversion to electromagnetic radiation. For a strong turbulence, this conversion is mainly associated with two processes: the direct conversion of long-wavelength upper-hybrid weaves on small-scale density gradients and coalescence of these waves into electromagnetic ones. Theoretical predictions are found to be in quantitative agreement with experimental results. |
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