Vol 9, No 1 (2010)
AIRCRAFT AND SPACE ROCKET ENGINEERING
Analysis of plane motion relative to the centre of mass of a descent capsule with the three-harmonic moment characteristics during its reentry
Abstract
The paper analyses plane motion of an uncontrolled descent capsule about its centre ofmass. The aerodynamic stabilizing moment of the spacecraft by an odd Fourier series by the angle of attack with the first three harmonics. A nomogram for determining the type and number of singular points of the system phase portrait has been constructed depending on the relation of coefficients at decomposition harmonics. Analytical formulae for the action integral taken along the separatrix, expressed through elementary functions and elliptical integrals of the first and second kind have been established. Themoments of transition between various areas of the phase plane have been determined. Formulae for assessing the possibility of capture into one region or another have been established for the cases of motion when the phase point may fall into various oscillation regions when crossing the separatrix.
9-19
Analysis of buckling of supported aircraft module skin under compressive load
Abstract
The paper deals with panels of aircraft riveted cylindrical module skin under axial compression. The aim of the research based on the finite element method is to establish the dependence of critical stress on the panel’s geometrical parameters that could be recommended for practical use.
20-27
28-33
Defining generalized reliability characteristics of complex technical systems including single-use subsystems
Abstract
Refinements in defining generalized reliability characteristics of a complex technical system including single-use subsystems are proposed. They are considered using the “launch complex-carrier rocket” system in conditions of its conversion usage as an example. Reliability characteristics are shown to improve in case the refinements mentioned are used. One of conversion rocket complexes is taken as an example.
34-37
Statistical analysis of a capsule’s motion during its reentry into the atmosphere with the aid of a space tether system
Abstract
The paper deals with the task of statistical analysis of a spherical capsule’s motion during its reentry into the atmosphere with the aid of a tether system deployed in the orbit. Statistical analysis includes the evaluation and analysis of the basic probability characteristics at the extra-atmospheric and atmospheric segments of the capsule’s flight after it is separated from the orbital tether system. The emphasis is on the analysis of the tether system’s influence on the evaluations and distributions as compared to classical descent schemes. The influence of the angle of the tether’s deviation from the vertical on the scattering of landing points is determined.
38-46
Solving the problem of stabilizing program deployment of an orbital tether system taking into account limitations on the rotary motion of the tip body
Abstract
The paper deals with the problem of stabilizing programme deployment of a space tether system with regard to limitations on the tip body rotary motion. The method proposed is based on direct calculation of the parameters of an optimal regulator using a non-linear model of tether system motion. A criterion of optimality is proposed that makes it possible to take into account the limitations specified when solving the stabilization problem. An example of calculating optimal feedback coefficients is given and the approach described is shown to enable considerable improvement of transition processes that arise in controlling the tether system deployment.
47-57
Development of information support for the spacecraft controlalgorithm design process
Abstract
Issues connected with information support for the control algorithm design processes during the development of on-board control complexes for space vehicles are in the discussed article. The main method proposed to solve the problem mentioned is to establish conformity between on-board equipment and control algorithms that have to execute a certain task.Development of full information support for the spacecraft’s design has the purpose of improving the operational characteristics of a spacecraft.
58-62
Research of dynamics of initiation, propagation, growth and closure of bubble cavities and a supercavity in a pipe with decontaminated liquid under hydraulic impacts
Abstract
For characteristic cross-sections of a simple pipeline with cavitating decontaminated liquid (near the supply capacity (x=0), in the middle of a pipe (x=0,5L), near a completely closed throttle (x=L), where x is a longitudinal coordinate, L is the length of the pipe) and for characteristic times (t) of the development of processes of cavitation (at the maximum length of the cavitation zone (tkm), at the maximum total volume of bubble cavities (tw) with full closing of all cavitational cavities (tc)) dependences of changes over X and t during two cycles of total volumes (W∑), of bubble cavities, supercavity volumes, (Wφ2) steam-content (a), speeds of a sound (a), a true pressure (P') and the mass expense (G) of a liquid or the steam-and-liquid mixtures are given. They are calculated according to the methods developed by the author, presented in [4]. The analysis of these dependences which reveals the dynamics of cavitational processes in a pipe with cavitating decontaminated liquid under hydraulic impacts is given.
63-74
Control programs and motion trajectories of hypersonic first stage of an aerospace system
Abstract
Control programs and motion trajectories of the hypersonic first stage of an aerospace system are defined using the maximum principle. The aim is to reach maximum velocity at a given trajectory slope and altitude.
75-83
84-90
91-96
Complex approach to mechanical tests of executive automatic units of space vehicles
Abstract
The problem of qualification of space vehicle units according to their resistance to mechanical influences is examined. For units having elements with a low natural frequency, an approach supplementing independent tests by the dynamic analysis in view of the way of their integration into a design of a space vehicle is proposed. The result of the dynamic analysis is confirmed by testing the units in the case under consideration the equaliser of volume in an active thermal control system, in the structure of a space vehicle model for dynamic tests, and the content of the program of independent tests of such a unit is established on the basis of the given approach.
97-102
Choosing the structure of power-supply systems for low-orbit space vehicles
Abstract
A methodology for analyzing and choosing the optimum structure of power-supply systems (PSS) for loworbit automatic spacecraft (SС) is considered. The expediency of using a universal parallel-serial structure which provides a possibility of extreme power regulation of solar batteries, at objects with varying operation conditions and sharply-variable load curves is justified. Design guidelines for structurally functional block-modular construction of a system with increased power capacity are proposed on the basis of parallel connection of energy subsystems.
103-113
MECHANICAL ENGINEERING AND POWER ENGINEERING
The influence of operational and technological factors on the dynamic parameters of elastic elements of elastic damping rotor supports
Abstract
The paper reports on operational and technological factors that influence the stiffness of an elastic element of the “squirrel cage” type. The influence of tolerances of the elastic element’s geometrical parameters on the stiffness coefficient of the structure is assessed. A refined procedure for the elastic element stiffness calculation is proposed.
114-119
Analysis of group properties of roller interaction in bearings using statistical
Abstract
The paper describes a statistical experiment in realization of roller race profiles of a tricone bit bearing. Bench tests have been carried out and the statistical data obtained are processed using harmonic and correlation analysis.
120-125
126-132
Dynamic analysis and optimization of turbojet engine nozzle control mechanism
Abstract
133-139
Tooling system of express assessment of explosive military equipment objects after hitling effects
Abstract
The paper deals with the principles of constructing, the structure and main tasks of the system of express assessment of the state of explosive military equipment objects after the enemy’s hitting effects. The proposed tooling system of on-line diagnostics increases the efficiency of armament maintenance and can be used as an additional safety component when dealing with explosive products as well as products presenting chemical or fire hazard.
140-144
Compulsory ignition of fuel-air mixture in small-sized gas turbine engine combustion chambers
Abstract
The paper deals with the peculiarities of compulsory ignition of fuel-air mixture in small-sized gas turbine engine combustion chambers. Physical and mathematical models have been developed. The regularities of stable ignition of one-phase and two-phase fuel air mixture have been established and its range estimated.
145-154
Peculiarities of gas temperature field formation at the exit of small-sized gas turbine engine combustion chambers
Abstract
The paper presents the results of investigation of the aerodynamic flow structure and hydraulic losses in combustion chambers of small-sized gas turbine engines. The influence of design parameters and operating conditions on the exhaust gas temperature field is shown.
155-160
Defining the specific impulse of mixed solid propellants
Abstract
The paper analyses the dependences of energy characteristics of non-metal compositions based on high-enthalpy hydrogen-free oxidizers on the heat capacity and chemical composition of the oxidizer, as well as on the type and amount of the coupler.
161-165
Determining the interrelation between detonation characteristics indicators and electrodynamic parameters of hydrocarbon fuels on the basis of statistical modelling of componental structure
Abstract
The paper deals with the componental structure of hydrocarbon fuels and their relation to detonation and electrical characteristics. Limiting and weighted average ranges of variation of dielectric permeabilities of standard petroleum brands with different additives present are calculated.
166-173
Obtaining the analytical solution of the heat boundary layer equation based on introducing additional boundary conditions
Abstract
A method of obtaining an approximate analytical solution of the initial differential equation (Polgauzen equation) has been developed using a mathematical model of the heat boundary layer presented in the form of Kruzhilin integral equation on the basis of introducing additional boundary conditions. The method developed makes it possible to obtain solutions with the specified degree of accuracy. Criterial dependence for defining the convective heat exchange coefficient at the fluid-wall boundary has been refined, the formulae for defining the heat boundary layer have been revised. Isotherm distribution within the heat boundary layer has been analysed, the velocity of isotherm motion along the transverse coordinate depending on the value of the longitudinal variable has been investigated.
174-184
Model of electromigration in thin metal films
Abstract
Causes of failure of the commutation structure of electronic devices based on thin metal films have been analysed. Electromigration processes are shown to be the basic factor leading to the failure of thin-film aluminium metallization. The mechanism of electromigration degradation of this king of metallization is analysed. Methods of improving electromigration reliability of metallization are also analysed. A model of electromigration processes based on a cellular machine has been developed, which makes it possible to model the process of flaw development in a thin film when subjected to high-density current and to measure the mean time to failure of thin-film conductors.
185-194
Optoelectronic device for the control of hydrocarbon fuel cavitation treatment
Abstract
The paper is devoted to improving the quality of hydrocarbon fuel by means of treatment in cavitation apparatuses. A survey of cavitation mixers available is given. A way of controlling operation modes of various cavitators is proposed so as to increase the dispersivity of water-fuel emulsion and the content of light fractions in petroleum products.
195-201
ELECTRONICS, MEASURING EQUIPMENT, RADIO ENGINEERING AND COMMUNICATION
Rail line models for adaptive receiver track circuits
Abstract
The paper deals with models of rail lines that can be used to analyse and calculate adaptive track circuits. Criteria of evaluating the state of adaptive track circuits are given. Adaptive track circuits with concentrated and distributed shunts are shown to substitute for typical rail lines with a concentrated shunt. The models described are used to analyse the methods of controlling adaptive track circuits.
202-208
Measuring scatlering cross-section under poor anechoicy conditions
Abstract
The paper deals with a technique that makes it possible to measure the scattering cross-section of objects in production rooms having no special radioabsorbing surfaces. The technique is based on measurements in the frequency domain with the transition to the time domain using Fourier transformations, filtration and inverse transition to the frequency domain. Data on scattering cross-section are obtained in a wide range of frequencies in one cycle of measurements. Experimental data are presented.
209-215
Quality indices of an internal combustion engine controlled by the discharge current channel
Abstract
The paper is devoted to the analysis of quality indices of automobile compulsory ignition internal combustion engines (ICE). The paper deals with the problems related to variations in fuel consumption and amount of exhaust gases when the ICE operation modes are controlled by the discharge current channel. The results of experimental analysis of quality indices for both serial and perspective piston engines are given. Complex evaluation of the efficiency of ICE control by the level of electromagnetic disturbance radiated is also given.
216-221
Two models of rail lines for adaptive receiver track circuits
Abstract
Two models of rail lines for adaptive receiver track circuits, where the power supply is connected to the end or the middle of the line are presented. Circuit diagrams of track circuits are given, as well as equations that relate currents and voltages on the ends of the rail line, coefficients of track line quadripoles, and algorithms for track circuit calculation. A conclusion is drawn that a track circuit can operate if the isolation resistance is one quarter of the admissible value.
222-229
Mathematical model of an eddy current converter for testing discontinuous structure samples
Abstract
The paper presents the solution of a problem in calculating the parameters of an eddy current field when the eddy current transducer interacts with the homogeneous structure of the primary field with two extended elliptical cylinders. The expression derived for the vector potential makes it possible to calculate the strength of both magnetic and electric fields as well as the transducer parameters being introduced.
230-233
CONTROL, COMPUTER SCIENCE AND INFORMATION SCIENCE
234-243
Through optimization of branching trajectories in view of random disturbances
Abstract
The problem of through optimization of branching spatial trajectories of space transportation systems is considered in view of random atmospheric disturbances (variations of thermodynamic parameters and wind) and constraints on admissible areas of dispersion of separated parts fall points.
244-249
HUMANITIES
Choice of parameters of an engineering production preparation system
Abstract
250-256
System for assessing the consistency of radioelectronic device design and the manufacturer’s technology at the stage of mastering
Abstract
The paper proposes a system of factors that assess the consistency of radioelectronic equipment design and technological conditions of the manufacturer at the stage of the product mastering. The results make it possible to assess the product technological effectiveness, the continuity of technological decisions, as well as to define the directions of the design further perfection with the aim of reducing production costs.
257-261
262-270