Vestnik NSU. Series: Physics. 2012. V7, i 1

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

A. V. Arzhannikov, N. S. Ginzburg, V. Yu. Zaslavkiy, I. V. Zotova, P. V. Kalinin, S. A. Kuznetsov, A. M. Malkin, N. Yu. Peskov, A. S. Sergeev, S. L. Sinitskiy, V. D. Stepanov, M. Tumm DEVELOPMENT OF THE TWO-STAGE PLANAR FEM FOR THE TERAHERTZ BAND ON THE BASIS OF THE ELMI ACCELERATOR

Project of the two-stage FEM-generator based on the ELMI accelerator with two parallel sheet electron beams formed in a single cathode unit is under development currently. In this scheme the first beam is used in the low-frequency section of the FEM for generating of high-power 75 GHz radiation. This radiation than goes through the coupling waveguides to the second channel and operates as a pumping wave which scatter on the second beam into the terahertz band. Our paper is devoted to modeling of various stimulated scattering regimes in this high-frequency section. Regime of the selfamplified spontaneous emission (SASE) is considered as well as a generator with resonator for the scattered radiation formed with advanced Bragg structures, based on coupling of traveling and quasi-critical waves.

5

Physics of Field, Neutral and Ionized Gases

Sidorenko A. A., Zanin B. Yu., Postnikov B. V., Budovskiy A. D. Control of Flow Separation on a Wing Using Electrical Discharge

Separation control experiments on a rectangular wing were carried out using dielectric barrier discharge plasma at subsonic speed for chord Reynolds numbers between 0,35 and 1*10^6. Surface pressure measurements and flow visualization show that global flow separation on the wing can be mitigated or eliminated with the plasma actuators. The data were obtained for a wide range of angle of attack, flow speed, plasma excitation frequency and power. Various means of discharge influence on separated flow were investigated, including acoustic one.

15

Katasonov Ì. Ì., Ìotyrev P. À., Sboev D. S., Êozlov V. V., Evers Q. B. Development of the Wave Packets-Forerunners at the Straight Wing Boundary Layer

This work is devoted to the study of wave packets (forerunners) formed in straight wing boundary layers in the regions preceding a drastic change in the flow velocity inside the boundary layer, near the fronts of streaks. The investigations were carried out in the subsonic low turbulence wind tunnel. Measurements of the flow fields were carried out using a single-wire probe of a constant-temperature hot-wire anemometer. It was shown that the localized structures, which modeled artificially from incoming flow, generate streaks in a boundary layer. The wave packets (forerunners) are appears in the regions preceding a drastic change of flow velocity inside the boundary layer at the streaks fronts. The characteristics of the forerunners, affected by the external-flow pressure gradient, intensity of streak, and local velocity gradients near the front of the streak were investigated.

28

Terekhova N. M. Nonlinear Interaction of High-Intensity Disturbances into the Supersonic Boundary Layer

A nonlinear model of interaction of disturbances in the regime of coupled combinatorial relations is used to explain the dynamics of unstable waves. The model includes effects of self-action and combinatorial interaction of unstable
waves. Considered effects in the boundary layer with M = 2 controlled disturbance large enough intensity. In the second case when M = 5,35 examines the interrelationship of two-dimensional perturbations of various nature – vortex and acoustic. Shows the direction of impact of the different components of the nonlinear process. Found that this model of the second order nonlinearity can accurately describe the features of longitudinal dynamics of plane waves.

38

Dulin V. M., Kozorezov Yu. S., Markovich D. M. Evaluation of Turbulent Kinetic Energy Dissipation Rate in a Free Jet Flow from PIV Measurements

The present paper reports PIV (Particle Image Velocimetry) measurements of turbulent velocity fluctuations statistics in development region of an axisymmetric free jet (Re = 28 000). To minimize measurement uncertainty, adaptive calibration, image processing and data post-processing algorithms were utilized. On the basis of theoretical analysis and direct measurements, the paper discusses effect of PIV spatial resolution on measured statistical characteristics of turbulent fluctuations. Underestimation of the second-order moments of velocity derivatives and of the turbulent kinetic energy dissipation rate due to a finite size of PIV interrogation area and finite thickness of laser sheet was analyzed from model spectra of turbulent velocity fluctuations. The results are in a good agreement with the measured experimental data. The paper also describes performance of possible ways to account for unresolved small-scale velocity fluctuations in PIV measurements of the dissipation rate. In particular, a turbulent viscosity model can be efficiently used to account for the unresolved pulsations in a free turbulent flow.

53

Berdnikov V. S., Mitin Ê. À. The Convective Conjugate Heat Transfer in a Vertical Liquid Lay

ÈAgency of finite boundaries heat conductivity on current structure and on local characteristics natural convection boundary layers in a vertical layer of fluid with walls, heated to different temperatures, over the range of Grashof numbers
100 < Gr< 10^4 is investigated. The equations of buoyancy induced convection in Boussinesq approach are solved by a method of finite elements in variables temperature, a vorticity and current function. The laminar flows in vertical layer are numerically investigated at boundary conditions of the first sort and in the conjugate statement of problem. In the latter case temperature fields, both in a liquid, and in firm vertical walls are counted.

70

Solid-State and Semiconductor Physics, Physics of Nanostructures

 

Boyarsky L. A., Fadin A. K. On the Vortex States IN A Nanoscale Ferromagnet CoPt

The nature of the vortex magnetic structure and the linear character of the magnetization curve of the ferromagnetic CoPt nanocrystals are explained in the framework of the Dzyaloshinskii – Moriya theory. The shape of the hysteresis
curve associated with the defects and impurities in the lattice.

80

Computer Science, Information-Communication Technologies

 

Budnikov K. I., Kurochkin A. V., Kubkov A. A., Yakovlev A. V. A Method for Experimental Estimation of E-mail Monitoring Sensors

The paper describes a method for experimental estimation of email monitoring sensors. Characteristics of a device are obtained while it processes an artificial workload, which parameters reflect statistical properties of real Internet email data streams. Three types of workload are suggested that correspond to 3 different types of a sensor connection to a communication network. A method of workload traffic generation is considered.

87

Baldin E. M., Blinov V. E., Zaitsev A. S., Korol A. A., Logashenko I. B., Sukharev A. M., Talyshev A. A., Tikhonov Yu. A. Super Charm-Tau Factory: Computing Requirements

Super Charm-Tau Factory (CTF), the project of e+e– collider with luminosity of 10^35 1 cm–2/sec–1, is being developed in the Budker Institute of Nuclear Physics (Novosibirsk, Russia). The main requirements and parameters for the
computing infrastructure of the future facility are discussed.

94

Educational and Methodical Provision of Teaching of Physics

V. À. Alexandrov THE FIRST ACQUAINTANCE WITH THE TENSOR
The main concepts of the theory of tensors are presented. The emphasis is on the basic notions of tensor algebra and practical skills in culculations involving the Kronecker delta and Levi-Civita symbol. Sixty routine exercises are included. This article is intended for junior students of physical, mathematical and geophysical departments of Universities.

 

100

Our Contributors

118

Instructions to Contributors

121

Âåðíóòüñÿ íà ãëàâíóþ