Vol 2, No 1 (2003)
AIRCRAFT AND SPACE ROCKET ENGINEERING
DYNAMIC PROCESSES IN ROCKET - SPACE SYSTEMS
Abstract
Dynamic processes in rocket - space systems such as rocket carriers and side blocks, small re-entry capsules with double rotation, also in auxiliary elements such as separation systems, solar batteries and antennas aperture systems (both with and without taking into account suspension elasticity) are discussed. Mathematical motion models are developed, dynamic processes are analyzed and parameters are synthesized in side blocks separation systems, in head fairing of rocket carrier and in solar battery panels. Re-entry capsule with double rotation is treated as a mechanical system of co-axial bodies with variable mass, having linear regularities of change of mass and moments of inertia.
STRUCTURE STIFFENING BY TOPOLOGICAL CHANGES
Abstract
Enhancement of structure stiffness characteristics due to the addition of new elements is considered. Theoretical analysis of heuristic actions of a designer faced with this kind of problem is given. Formalized algorithm for the search of additional elements is proposed.
COMPUTING VORTICITY DIFFUSION WITH A MODIFIED "DONOR-ACCEPTOR" SCHEME AND THE INTEGRATION OF THE SCHEME INTO THE "VORTEX-IN-CELL" METHOD
Abstract
A modernised scheme of splitting Navier-Stokes equations for the numerical method of "vortex-in-cell" is proposed. The method consists in introducing a minor parameter proportional to kinematic viscosity into the scheme. It allows finding the solution of the problem in the form of asymptotic series. An advection-diffusion problem of the Lamb-Ozeen vortex is considered for the verification of the proposed method. Computation results obtained by "donor-acceptor" (D-A) and MD-A methods are compared with an analytical solution of the advection-diffusion problem. The MD-A method is shown to be more suitable for low viscosity flow simulation. Unlike the D-A method, the MD-A method remains accurate in a wide range of space and time resolution.
TECHNICAL SCIENCES
INFLUENCE OF SCALE FACTOR ON THE FORMATION OF RESIDUAL STRESSES IN CASE OF THERMOPLASTIC STRENGTHENING
Abstract
REDUCTION OF TURBO-PUMP UNIT VIBRATION BY REGULATING BEARING RIGIDITY
Abstract
The paper discusses a multi-mass dynamic model "rotor-bearing-housing-basement" of a turbo-pump unit. The possibility of reducing vibro-velocity on the turbo-pump unit housing and the rotor oscillation amplitude due to changing bearing rigidity by longitudinal compression of an annular bearing is shown.
STRAIN DEFORMED STATE IN TURBINE DISC GROOVES UNDER THEIR THERMOSTRENGTHENING
Abstract
The paper presents the procedure and results of thermal stress state analysis in a turbine disc herringbone groove when it is subjected to thermoplastic strengthening. The thermoplastic strengthening method is found to create a propitious field of compression residual stress in a superficial layer of a part of any geometry complexity.
MATHEMATICAL MODEL OF HIGH-TEMPERATURE GAS DEVICE
Abstract
Mathematical model of a high-temperature compression device that allows quantitative d escription of the compression process in the installation has been developed. It can also be used to determine the optimal operation mode, to calculate the parameters of newly designed devices and to look for ways of radiation heat exchange intensification in ballistic plasmatrons. Numerical calculations of gas parameters in a high-temperature compression installation used for solid-state laser pumping have been performed. The results obtained are in agreement with the experimental data. They permit quantitative description of the compression and radiation process in the installation.
OPTOELECTRONIC DISCRETE PHASE METHOD FOR THE DETERMINATION OF TURBINE BLADE
Abstract
The paper describes the optoelectronic discrete phase method for measuring deformation of blades of rotating bladed-disc assemblies of turbomachines. Advantages and disadvantages of different versions of optoelectronic discrete phase method realization are dealt with. Acriterion relating parameters of the reflecting surface to the radiator wavelength and making it possible to formulate the conditions necessary for the implementation of the method is introduced. Several circuit diagrams of devices for the realization of the method are presented.
ANALYSIS OF NON-BAR BACK PULL DRAWING FOR THIN-WALLED TUBES
Abstract
Theoretical study of a non-bar back pull drawing process for thin-walled tubes has been carried out. A complete set of equations is given permitting the determination of both stress and deformation fields required for the proper selection of drawing parameter and the tool to be used.
STRUCTURE AND PROPERTIES OF ANNEALED AND TEMPERED STEEL AFTER RAPID ELECTROTHERMAL PROCESSING
Abstract
The structure and properties of steel 25 after heating it with high-density pulse current for hardening, the influence of cooling speed and high tempering on the stability of properties have been investigated.
CONTROLLING THICKNESS DIFFERENCES OF HOLLOW PIECES BY PLASTIC TOOLS
Abstract
Devices for controlling wall thickness of hollow pieces have been designed and patented. Thickness is increased due to wave pressure of surplus material by an elastic tool. A mathematical model of material redistribution and simple dependences for practical use have been proposed. The results of experimental investigations are given.
DETERMINING GEOMETRICAL PARAMETERS OF CENTRIPETAL MICROTURBINE NOZZLE CONSISTING OF RECTILINEAR BLADES
Abstract
PROCEDURE OF ESTIMATING PROBABILITY OF PIPELINE SYSTEM RELIABLE OPERATION
Abstract
Scientific departments and laboratories of Samara State Aerospace University have wide experience in ensuring reliability and defining safe life expectancy of aircraft structural elements. The paper provides the description of the procedure of estimating probability of reliable operation of different purpose pipeline systems. Measures permitting considerable reduction of operation loads and increase of reliability and durability are also described.
INFLUENCE OF REPEATED HEATING ON MECHANICAL AND TECHNOLOGICAL PROPERTIES OF SHEET ALUMINIUM ALLOY WITH A HIGH CONTENT OF MAGNESIUM
Abstract
A complex study of mechanical and technological properties of sheet items of deformable high-magnesium aluminium alloy is carried out. The possibility of its use for manufacturing aircraft and automobile products is estimated.
DIGITAL SPECKLE INTERFEROMETER FOR THE INVESTIGATION OF VIBRATION CHARACTERISTICS OF OBJECTS EXCITED SIMULTANEOUSLY AT SEVERAL FREQUENCIES
Abstract
The paper deals with the problems to be solved for the creation of a digital speckle interferometer that makes it possible to study vibration of mechanical elements excited simultaneously at several frequencies. The method of registering specklograms has been developed on the basis of methods of holography and speckle-interferometery. Separate spectral components of surface oscillations in case of broadband object stimulation are shown. The method developed is based on time modulation of laser beams in the interferometer.
PHYSICS AND MATHEMATICS
LINEAR ANALYSIS OF MATERIAL LAYER STATIONARY SEPARATION
Abstract
Characteristics of a stationary p rocess of directional separation have been constructed on the basis of thermomechanical analysis, their interrelation with the known destruction criteria has been established.
ONLY A FEW PROJECTIONS COMPUTED TOMOGRAPHY IN A PHYSICAL EXPERIMENT
Abstract
Methods, algorithms and examples of equipment realization of only a few projections 2D and 3D tomographic diagnostics of physical object parameters with reference to laboratory studies are presented. In particular, methods and algorithms of diagnostics of high-temperature plasma and plasma flows are described, results of investigating spatial distribution of admixtures in fires, examples of restructuring composite materials are presented.
CYBERNETICS AND INFORMATION SCIENCE
AUTOMATED COMPLEX OF PROCESSING TELEMETRY INFORMATION
Abstract
Automated complex of processing telemetry information is realized on the basis of a local network. Customer computers of the testers functioning in parallel are connected to the processing server on the basis of socket technology. Mathematical methods and graphic models for defining the time of executing standard jobs of telemetry information processing are proposed. A simulation model for the analysis of telemetry information processing system productivity has been developed.
HUMANITIES
THE DEVELOPMENT AND REALISING OF ECONOMIC STIMULATION IN INTRACOMPANY MECHANISMS OF MANAGING ENTERPRISES
Abstract
The aggregate of economic stimulation mathematical models is suggested, which allows setting and solving tasks of analysis and synthesis of multiparameter stimulation systems, evaluating the extent of their influence on the mechanisms of implementing planned tasks and the efficiency of functioning both of individual industrial elements and the system as a whole.
MEDICAL AND SOCIAL ASSISTANCE GIVEN TO REFUGEES BY AUTHORITIES AND SOCIETY DURING THE FIRST WORLD WAR
Abstract
Russian Government, State Duma, the public, the clergy, representatives of local government showed great concern for refugees during the First World War. Elaborated legal system concerning refugees, interaction of branches of authority, strict observation of their recommendations were of great help. The result was a considerable reduction of social tension among refugees. Problems of giving them medical help were also dealt with at congresses of Zemsky doctors (zemstvo - elective district council in Russia, 1864-1917). The experience of Russian pre-revolutionary state authorities and society is applicable to modern conditions during local and international military conflicts.
INSTITUTIONAL PROBLEMS OF HIGHER EDUCATIONAL MARKET FORMATION
Abstract
The article deals with some institutional problems of higher educational market formation. Subsystems of education and market segments of higher educational service are described, comparative characteristics of different types of higher educational establishments are given.
METHODOLOGICAL APPROACHES TO ASSESSING COMPETITIVENESS OF AN INDUSTRIAL ENTERPRISE
Abstract
Basic methodological approaches to assessing competitiveness of an industrial enterprise that takes part in foreign economic activity are considered. Analysis of the main indicators that influence the efficiency of a company's market activity is carried out, which makes it possible to assess the competitive status of the company. To be successful in the new market system based on direct competition with foreign companies home enterprises should adequately estimate their place in the system and clearly understand how well the intracompany scientific, production, technological, personnel and organizational resources conform to the current market needs and what can be done to achieve this conformity in the foreseeable future.