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Experimental and numerical investigation of controlled disturbances development from two sources in supersonic boundary layer

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Advances in Aerodynamics 2019年第1期1卷 288-300页

作者： G.L.Kolosov A.D.Kosinov A.N.Semenov A.A.Yatskikh khristianovich institute of theoretical and applied mechanics sb ras Novosibirsk 630090Russia

The paper presents the experimental results and the results of direct numerical simulation of the development and interaction of two wave trains from two point sources of controlled disturbances in a supersonic boundary layer on a flat plate with an incident flow Mach number of *** were located parallel to the leading edge of the *** the introduction of controlled disturbances into the boundary layer,the normal component of the mass flow rate was varied in the *** the experiment,periodic glow discharges at a frequency of 20 kHz were *** both cases,the disturbances sources worked *** flow rate pulsations were measured and recorded in sections,parallel to the leading edge of the model,near the maximum of disturbances along the boundary *** the experiment,a constanttemperature hot-wire anemometer was *** performing a discrete Fourier transform,the spatial distributions of disturbances,the beta-spectra were determined,and the wave characteristics of the development of disturbances downstream were *** addition,direct numerical simulation of the downstream development of disturbances from a single source was *** work presents a comparison of experimental and theoretical calculated *** paper discusses the effects inherent in the interaction of unstable traveling controlled disturbances from two sources operating synchronously.

关键词： :DNS Computational modeling Supersonic boundary layer Compressibility Discharge Flat plate Hot-wire anemometer Instability Turbulence

Experimental study of compressible boundary layer on a cone at angles of attack

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Acta Mechanica Sinica 2009年第3期25卷 325-333页

作者： A.Maslov D.Bountin A.Shiplyuk A.Sidorenko Q.Shen Z.Bi khristianovich institute of theoretical and applied mechanics(ITAM)and Novosibirsk State University China Academy of Aerospace Aerodynamics(CAAA)

Experimental study was conducted for boundarylayers on a sharp 5° half-angle cone of 400mm length at angles of attack. The model was tested in the T-326 hypersonic wind tunnel （ITAM） at freestream Mach number M = 5.95. Mean and fluctuation wall characteristics of the boundary layer are measured at 0°, 2°, 3° and 4° angles of attack for different stagnation pressures. Pulsation measurements are carried out by means of ALTP sensor. Pressure and temperature distributions along the model are obtained, and transition beginning and end locations have been found. Boundary layer stabilization with the increase of angle of attack and the decrease of stagnation pressure is observed. High frequency pulsations inherent to hypersonic boundary layer （second mode） have been detected.

关键词： Compressible boundary layer Transition,Experimental study

Linear Instability of the Supersonic Boundary Layer on a Compliant Surface

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Journal of applied Mathematics and Physics 2014年第6期2卷 253-263页

作者： S. A. Gaponov khristianovich institute of theoretical and applied mechanics sb ras Novosibirsk 630090 Russia

In the paper the influence of flexible covering properties on the linear development of disturbances in a supersonic boundary layer is investigated for Mach numbers M = 1.0, 2.0, 5.3, 6.0. As a model of a covering the porous plate closed by a flexible film is used. In the absence of gas in pores it is established that the flexible covering stabilizes boundary layer in the area of large Reynolds numbers and destabilizes it at small Reynolds numbers. Joint influence of the thickness and tension of a film leads to an appearance of additional unstable waves. For filled with gas pores the researches are conducted as taking into account losses of energy of disturbances in pores and in their absence. Calculations without power losses indicate possibility of existence of an absolute instability of the boundary layer on the flexible surface. The damping properties of a flexible covering connected with power losses in pores reduce their stabilizing role.

关键词： Compressible Boundary Layers Laminar-Turbulent Transition Hydrodynamic Stability

On the calculation of the electron temperature flowfield in the DSMC studies of ionized re-entry flows

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Advances in Aerodynamics 2020年第1期2卷 107-119页

作者： Alexander Shevyrin Yevgeniy Bondar khristianovich institute of theoretical and applied mechanics of the Siberian Branch of the ras 4/1Institutskaya Str.Novosibirsk 630090Russia

Currently available procedures of electron temperature calculations in studying ionized flows around reentry spacecraft by the direct simulation Monte Carlo(DSMC)method are *** is shown that the heat conduction of electrons is not taken into account in these *** contributions of various effects to the electron energy balance are calculated by an example of the RAM-C II capsule,and a numerical solution of the electron energy conservation equation is obtained,which refines the electron temperature distribution used in the DSMC computations.A method of coupled calculation of the electron temperature within the framework of the continuum approach and modelling of ionized gas flow by the DSMC method is proposed.

关键词： Energy transfer Ionized gases Low density flow DSMC method Plasma model Electron temperature High-altitude aerothermodynamics Continuum flow Non-equilibrium flow

Experimental study on vortex/bow shock interaction at Mach number of 6

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Experimental study on vortex/bow shock interaction at Mach n...

Simulation of Thermophysical Processes at Laser Welding of Alloys Containing Refractory Nanoparticles

23rd International Congress of theoretical and applied mechanics

作者： Andrey Shmakov Andrey Shevchenko Anatoly Kharitonov khristianovich institute of theoretical and applied mechanics sb ras NovosibirskRussia

＜正＞A review of a complex experimental study of various regimes during the interaction of the wing-tip vortex with the bow shock generated by the cylinder obstacle at Mach number of 6 is presented. Complex of experi...

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Advances in Materials Physics and Chemistry 2012年第4期2卷 270-273页

作者： Anatoly N. Cherepanov Vasily P. Shapeev Guangxun Liu Lamei Cao Beijing institute of Aeronautical Materials Beijing China khristianovich institute of theoretical and applied mechanics sb ras Novosibirsk State University Novosibirsk Russia

Mathematical model is formulated for description of thermophysical processes at laser welding of metal plates for the case when modifying nanoparticles of refractory compounds (nanopowder inoculators – NPI) are introduced into the weld pool. Specially prepared nanoparticles of refractory compounds serve here as crystallization centers, i.e. in fact they are exogenous inoculants on which surface clusters are grouped. This can be used to control the melt crystallization process and formation of its structure, and, therefore, properties of the weld seam. As an example, calculation results of the butt welding of aluminum alloy and steel plates are presented. The results of calculation and experimental data comparison are shown.

关键词： Mathematical Model Laser Welding Nanopowder Inoculators Crystallization Process Calculation Results

High Speed Boundary Layer Stability and Control

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High Speed Boundary Layer Stability and Control

The Dependence of Stellar Activity Cycles on Effective Temperature

第六届国际流体力学会议

作者： A. A. Maslov khristianovich institute of theoretical and applied mechanics sb ras Novosibirsk 630090RussiaNovosibirsk State UniversityNovosibirsk 630090Russia

In the present paper an overview of the recent studies of a hypersonic laminar boundary layer and shock layer receptivity and stability are *** attention is paid to investigations of nonlinear wave *** is shown that nonlinear interactions of the second mode play significant role in laminar-turbulent transition and intermode interaction is different for solid and porous *** paper deals with two different techniques of transition *** first one,namely,ultrasonically absorptive coating（UAC） is a passive technique which uses porous materials on the wall to suppress growing acoustic disturbances in the boundary *** second one is based on wave interference and intermode interaction and uses blowing-suction method to suppress acoustic in the boundary layer.

关键词： boundary layer shock layer disturbance development nonlinear interaction passive and active distur-bances control

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Research in Astronomy and Astrophysics 2022年第12期22卷 198-210页

作者： Leonid Kitchatinov institute of Solar-Terrestrial Physics sb ras Lermontov Str.126AIrkutsk 664033Russia

This paper proposes the idea that the observed dependence of stellar activity cycles on rotation rate can be a manifestation of a stronger dependence on the effective temperature. Observational evidence is recalled and theoretical arguments are given for the presence of cyclic activity in the case of sufficiently slow rotation only. Slow rotation means proximity to the observed upper bound on the rotation period of solar-type stars. This maximum rotation period depends on temperature and shortens for hotter stars. The maximum rotation period is interpreted as the minimum rotation rate for operation of a large-scale dynamo. A combined model for differential rotation and the dynamo is applied to stars of different mass rotating with a rate slightly above the threshold rate for the *** show shorter dynamo cycles for hotter stars. As the hotter stars rotate faster, the computed cycles are also shorter for faster rotation. The observed smaller upper bound for rotation period of hotter stars can be explained by the larger threshold amplitude of the α-effect for onset of their dynamos: a larger α demands faster rotation. The amplitude of the(cycling) magnetic energy in the computations is proportional to the difference between the rotation period and its upper bound for the dynamo. Stars with moderately different rotation rates can differ significantly in super-criticality of their dynamos and therefore in their magnetic activity, as observed.

关键词： dynamo stars:activity stars:magnetic field stars:solar-type stars:rotation

On Prime Spectrum of Maximal Subgroups in Finite Groups

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Algebra Colloquium 2018年第4期25卷 579-584页

作者： Chi Zhang Wenbin Guo Natalia V.Maslova Danila O.Revin Department of Mathematics University of Science and Technology of ChinaHefei 230026China Krasovskii institute of Mathematics and mechanics UB ras and Ural Federal University Yekaterinburg 620990Russia Sobolev institute of Mathematics SB RAS and Novosibirsk State University Novosibirsk 630090Russia

For a positive integer n,we denote byπ(n)the set of all prime divisors of *** a finite group G,the setπ(G):=π(|G|)is called the prime spectrum of *** M 详细信息

For a positive integer n,we denote byπ(n)the set of all prime divisors of *** a finite group G,the setπ(G):=π(|G|)is called the prime spectrum of *** Mtheoretical results,we present a number of examples to show that both K(G)and k(G)are unbounded in *** implies that the problem"Are k(G)and K(G)bounded by some constant k?",raised by Monakhov and Skiba in 2016,is solved in the negative.

关键词： finite group finite simple group prime spectrum maximal subgroup