2012. № 53
Mathematics. Physics. Mechanics | |
A problem of obtaining of physical-mechanical properties of a media using boundary measurements of displacements and thermal fields is considered. The problem is solved in a periodicstatement. An equation binding unknown values to the boundary displacements field is constructed. The field geometry and boundary conditions allow to reduce the problem to an one-dimensional thermoelasticity problem. Resolving equations from which desired values can be obtained are constructed using a finite Fourier's transform of a spatial variable. These equations represent a systme of non-linear algebraic equiations and are solved using numeric methods. Keywords: thermoelasticity, inverse problem, quotients problem, non-correct problems |
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The kinematics of perturbation in a porous elastic half-plane object is studied here. It includes two components: the deformation of the frame and the compressible fluid located in the pores. The Biot model is applied in order to get the solution. We use Fourier spatial coordinates and Laplace transform in time. The originals can be found in the case of one-direction and above the surface of the half-plane. In the latter case, algorithm is used to invert changes together of Laplace and Fourier, which are based on the construction of analytical representations of the images. Keywords: biot model; surface influence application, Laplace and Fourier integral transformation of the Laplace and Fourier transforms, elastic-porous materials. |
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Axisymmetric kinematics of perturbation from the surface of a sphere filled with homogeneous isotropic medium with restricted rotation (the Cosserat pseudo-continuum) are considered. These models are used in the study of the behavior of different structures, which are made from composite materials, including objects of aviation, rocket and space technology. In order to find out the solution, we use a serial expansion in Legendre polynomials and Laplace transform of the time. To find the original function we use asymptotic method – representation of functions as power series in time, which corresponds to expansion of the image of functions in a Laurent series in a neighborhood of infinity Keywords: the Cosserat pseudo-continuum; Laplace transform; axial symmetry; the asymptotic solutions. |
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Charging model of the dielectric thin film by electron beam is based on currents balance in the dielectric: charging current of absorbed electrons and discharging current of space charge electric field of accumulated electron. During electron irradiation dielectric discharge is facilitated by the fact that the dielectric irradiation conductivity is increased by several orders of magnitude compared to the dielectric conductivity before irradiation. The calculations of the electric field in the dielectric film which is charged by a pulsed electron beam with an energy of 80 keV, average current density of 0.1 µA/cm2 and dose rate 670 Gy/s are presented in the paper. Dielectric charging depends on the ratio of electron mean free path and film thickness, surface, dose rate, the secondary electron emission from the film surface and the irradiation conductivity. Keywords: polymer films, electron beam, irradiation conductivity, dielectric charging, electrical breakdown |
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Aviation technics and technology | |
The formation of an approach to automated prototyping of large objects is described in article. Classification of models is described; existing methods of modeling were analyzed, the scope of automated layout techniques of large objects was revealed. The technic of modeling, based on the developed software module "Maket" has been proposed in the study. Keywords: aviation; frame; prototyping; method; module; surface; CAD. |
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The simulation approach of water discharge from helicopter liquid tank on external load (EL) is proposed in this article. The application program FlowVision is used for numerical experiment. The experiment-calculated procedure for lifting rotor (LR) velocity field estimation is suggested. This procedure is based on real LR experimental data for different helicopter airspeed and known vertical speed versus radius in LR plane. There is supposed absolute rigidity of liquid tank and rope. The fire is burning round cylinder oil storage tank. The numerical experiment with Ka-32 helicopter is getting for presentation of this simulation approach. This helicopter is moved rectilinearly and evenly with airspeed 38 km/h. This numerical experiment procedure can used for fire-fighting helicopter design and operation analysis. Keywords: a helicopter; a liquid tank; a computing experiment |
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The possibility of application of modern software package for computational fluid dynamics (CFD - Computational Fluid Dynamics) for the purpose of designing axial fans has been studied. It is shown that the use of Realizable turbulence model gives results in better conformity with experimental data than the model SST . The effect of the number of blades on the mass flow - dynamic pressure characteristics of a given geometry of the fan, as well as the use of the second propeller in order to improve the efficiency of the axial fan has been analyzed. Keywords: axial Fan, the Reynolds-Averaged Navier-Stokes Equations, the Method of SIMPLEC, the Coefficients of the Total Pressure and Productivity Efficiency and Power Factor of the Fan. |
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Research shows the calculation of the aerodynamic characteristics of hypersonic vehicles in the transitional regime with a local engineering method. This problem is particularly important when aircraft is moving at high altitudes. This paper proposes to create a simple engineering program for calculation of aerodynamic characteristics of different body shapes. In this paper presents the aerodynamic calculations of hypersonic vehicles using the local method with various Reynolds numbers. Keywords: aerodynamics in the transitional regime, the aerodynamic characteristics of hypersonic vehicles, the Reynolds number, the hypothesis of locality |
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Technical cybernetics. Information technology. Computer facilities | |
Development in a short time and with the minimum expenses of the specialized program systems providing information support of automated workplaces of production and design space-rocket systems is an actual task of the enterprises of branch on a way to increase of competitiveness of made production and reduction of terms of its delivery to the consumer. IDEF0 and procedural charts are used for modelling the process of design of the automated system for milling processing a compartment of an anti-aircraft missile on the NC machine with use of the universal program tools realizing possibilities of a nonprocedural programming language. Keywords: technical training of production; the automated systems of production; IDEF0 methodology; tables of decisions |
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Features of use of computer graphics in computing experiments for the purpose of increase of their efficiency on an example of problems of mechanics and electrodynamics backgraund plasmas are considered. It is discussed methodical questions of use of computer graphics at all stages of preparation, carrying out and the analysis of results of computing experiment. Keywords: backgraund plasma; computer graphics, distribution function, a field of speeds, isolines, a settlement grid, a step on time, test calculation |
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This article compares two methods of passive optical location in application for range estimation. Basic stages of algorithms and implementation details are described. Article examines numerical simulation results and reason for development of complex range estimation algorithm. Keywords: unmanned aerial vehicle; passive optical methods of range estimation; geometric triangulation; variational approach |
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Aerospace propulsion engineering | |
Experimental investigations of direct laser ignition of non-hypergolic components in model combustion chamber are conducted. Two ways of mounting of laser on combustion chamber are investigated - axial attachment to nozzles head and mounting on lateral chamber surface. Results of experiments with following couples of propellants are described: oxygen-hydrogen, oxygen-methane, oxygen-ethanol, oxygen-70% solution of ethanol in water. Keywords: laser ignition, laser breakdown, combustion chamber, nozzles head |
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It was suggested the classification of losses in blade grids of axial small size turbines and the methodic of evaluation of channel losses their. Keywords: small size turbine blade grids; losses in blade grids; methodic of evaluation of losses; small seale. |
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Theoretical engineering. Mechanical engineering | |
On the Stabilization of the Robot with Deformable Wheels with Incomplete Information about the State
Keywords: analytical mechanics, stabilization, incomplete information about the state, wheel planetary rover, differential drive, deformable wheel. |
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Control systems | |
This paper investigates robust stability control systems aircraft, built in the three-parameter classes of structurally stable maps with control law, given in the form of disaster “hyperbolic umbilic”. Stability analysis is based on linear approximation and the use of algebraic Hurwitz criterion. It is shown that the introduction of the control law in the form of disaster “hyperbolic umbilic” motion control system of the aircraft becomes resistant to external disturbances and noise in all the unknown parameters of the object control and set parameters of the regulator. The results are confirmed by numerical experiment conducted on the basis of the program complex Vissim 6.0. Keywords: stability, robustness, catastrophe, a steady state, the Hurwitz criterion, aircraft |
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Navigation systems | |
Expression of a methodical error of measurement by a wave solid-state gyroscope with differentiation
Measurements by separate channels of integrating wave solid-state gyroscopes with differentiation (VTG-IGD) with the task of constant angular speed ( ) have found out a periodic hindrance with a prevailing harmonic, the amplitude and which frequency are proportional . Such phenomenon can be caused poor-quality formation and (or) transformation of the signals arriving from gages of a corner ( ) positions of a standing wave on two channels. Thus target signals can functionally look like: Аs=А1•sin2 + c1, Ac=A2•сos2 + c2, also there is a periodic error ( ). It is shown that the amplitude of a harmonic sin4 is proportional |А1–А2|/(А1+А2). Functions of the measured corners and (turn of the basis of a gyroscope) from and dependences of the measured corners , increments of a corner , speed of change on time are received at the task . The analysis of skilled parameters of a hindrance is carried out. Keywords: a methodical error, the periodic hindrance, the integrating wave solid-state gyroscope integrating a wave solid-state gyroscope with digital differentiation, the measured (counted up) values, a corner of position of a standing wave, an angle of rotation, angular speed. |
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The analysis of formation and passage of signals of orientation of a standing wave on sinus and cosines to channels from the resonator to analog-digital converters (АЦП) in a wave solid-state gyroscope (ВТГ) is carried out at motionless basis ВТГ. Using electric analog of mathematical model of the condenser of variable capacity and a symbolical method of calculation of electric chains, analytical dependences of signals on inputs of buffer amplifiers from parameters of measuring chains of capacitor gages are found at their food from sources constant and an alternating voltage. Expressions of signals of orientation from exits АЦП taking into account presence of deviations of factors of transfer and zero signals of intermediate blocks are received. Research of influence of the specified errors on a periodic error of measurement of a corner of orientation of a standing wave is conducted. Keywords: an integrating wave solid-state gyroscope, a corner of position (orientation) of a standing wave, a methodical periodic error, a signal, capacitor gages of radial moving of a cover of the resonator, the buffer amplifier, the differential amplifier-adder, the synchronous detector, the analog-digital converter. |
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The article deals with the functionality of the simulator signals SRNS IM-2, confirming the possibility of using the simulator for solve the problems in estimating the angles of spatial orientation definition objects. We derive expressions for the pseudoranges and pseudoranges double difference from the assumption of different time between time the formation scenario simulator and the arrival time of a signal to the navigation receiver, identifies the amendment to the classical equations describing the pseudoranges double difference. It was established experimentally that mathematics IM-2 simulator is that to solve the problems of assessing the orientation angles of objects to use half-amendments to the classical formulas. Keywords: GPS, highly dynamic objects, signal simulator, amendments, orientation definition, pseudoranges. |
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Radio engineering. Electronics. Telecommunication systems | |
The dependence of load in a mobile radio network`s cell from the angle of the directivity pattern at the base station (BS) is analyzed in this article. Main characteristics of the antenna technology, which most affect on performance load cell are determined. The prospects for the use of smart antenna systems are investigate in conjunction with algorithms for early detection of local overloads on the basis of subscriber`s mobility the parameters. Keywords: analysis of the dependence of load in the cell; smart antenna algorithm for early detection of local overloads. |
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Economics | |
The problems of Russian aircraft industry development strategies’ scientific substantiation methodology improvement are considered. The priority directions of aviation development prospects’ systemic strategic research are determined. Keywords: the problems of Russian aircraft industry development strategies’ scientific substantiation methodology improvement are considered. The priority directions of aviation development prospects’ systemic strategic research are determined |
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The paper presents methods for constructing a system of corporate governance in integrated missile and space industry. The problems in the management holding company, and the mechanisms of internal corporate governance. They allow you to effectively implement the package of measures to the most significant areas of activity of the corporation. Keywords: mechanism of corporate governance, rocket and space industry of Russia |
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The problem of a strategic choice on an example of the enterprises of the industry creating means of production and defining technological way of a national economy is considered. The special place in industrial production is occupied with the aviation branch providing competitiveness of the country on a world scene. In article the mechanism integrating strategic, design and operatively - the tactical planning is offered, allowing integrally to connect strategic installations of development of the consolidated enterprises and their practical realisation. Keywords: strategy; strategic changes; the project; the plan; system of plans; business-plan; planning horizon; perspective and operatively-tactical plans of the enterprises and the organizations. |
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Article touches upon with a set of national and foreign Foresight projects devoted to future development of aviation industry including S&T Foresight until 2025, launched by the Institute for Statistical Studies and Economics of Knowledge, National Research University “Higher School of Economics” (ISSEK HSE). Special attention focuses on Roadmap “Use of nanotechnologies in aviation industry”. Keywords: aviation, Foresight, Roadmaps, innovation strategies |
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The economic mechanism of management of research and development on working out of flying machines of near and far space is considered in article. Keywords: economic mechanism of management of research and development; flying machines; planning; pricing; insurance. |