Vol 14, No 4 (2015)

Full Issue

AIRCRAFT AND SPACE ROCKET ENGINEERING
Method of creating digital terrain models and its practical application as exemplified by Samara region
Anshakov G.P., Myatov G.N., Malinovskii V.A.
Abstract

The article shows that high accuracy is one of the most important elements in the technology of creating such information products as a digital elevation model (DEM) of the terrain, so a reference is to be provided to confirm the accuracy. Unlike the methodological approach based on collecting data on the terrain relief using digitized topographic maps, a procedure is proposed to generate a reference DEM. The procedure provides high accuracy in solving the problem of coordinate referencing of control points due to differential processing of the navigation information obtained with the help of dual-frequency receivers of the geodetic class. In the course of work a technique for obtaining precise contour intervals of the terrain based on a rigidly bound algorithm for combining inertial and satellite measurements providing high-precision solutions even in the temporary absence of satellite signals was developed and experimentally validated. As a result of field and office works conducted in 2013-2015, a reference DEM with a size of about 50 × 50 km2 was established that made it possible to evaluate the results obtained by DEM space stereo photography and make appropriate corrections in the program and methodical apparatus of  Earth remote sensing data processing.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):7-16
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Bypass as an attribute of unmanned spacecraft operability in anomalous flight situations
Akhmetov R.N., Makarov V.P., Sollogub A.V.
Abstract

The bypass factor as the basis for providing Earth remote sensing spacecraft (ERS SC) operability in anomalous flight conditions, related with onboard equipment (OE) faults, is discussed in the paper. In addition, operability as a complex property is decomposed into three particular characteristics: invulnerability, adaptability, and recoverability. Principles of their implementation during the flight are based not only on structural provisions (for example, protective measures), but also on OE technical state control not only by integrated structural reserves, but also by bypasses based on other resources. Provision of ERS SC operability and target operation with the use of minimum additional resources is the purpose of bypass control in anomalous flight situations. It is based mainly on roundabout ways of accomplishing tasks, in other  words, on bypasses produced on the basis of functional, information-analytic, and natural resources (intrinsic to OE) as well as emergent (synergetic) resources formed as a result of purposeful interaction of dissimilar components, in particular, the complex of the SC onboard equipment. The topicality of this problem increases with the decrease of ERS SC weight-dimension characteristics (caused by tightening the restrictions) and the increase of active life duration (Tаl) under relatively strict requirements of efficiency target (ET). Variants of using available OE redundancies for ERS SC bypass flight control, taking into account the change of ET within the set limits, are proposed in the paper. Schemes of numerical estimation of efficiency and operability as vector parameters on the basis of bypasses including those based on parameters and criteria of SC operability are presented. A possibility of forming requirements to onboard equipment to ensure SC operability in anomalous flight conditions with their help is shown.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):17-37
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Procedure of accomodation of earth remote sansing satellite external devices with regard for the satellite target operation
Akhmetov R.N., Shilov L.B., Kurenkov V.I., Yakischik A.A.
Abstract

The paper dials with the problem of accommodation of external devices of the Earth remote sensing satellite (ERSS). It is shown that it has a significant influence on the ERSS conceptual design and target characteristics of a space system as well as partial efficiency indices of the support systems.  Models and algorithms have been developed which allow estimating partial efficiency indices used for choosing the sites and angles of installing the devices. Among these devices are solar cell battery panels, radiators, star trackers, laser intersatellite link devices, satellite navigation system antennas, etc.  Partial efficiency indices used for the appropriate accommodation of the external devices are assessed with the help of the software based on the simulation of the satellite orbital motion, conditions of its operation, target turns, and interaction with other objects of the orbital constellation. Some results of testing the proposed procedure are given. As an example, it is shown that for ERSS with sun synchronous orbits the average cosine of the angle between the Sun line and normal to the plane of the solar cell battery depends upon the longitude of ascending node to a great extent.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):38-48
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Choosing a program for controlling the deployment of an orbital tether system with deployment speed limitations
Ishkov S.A., Xiaoye X., Filippov G.A.
Abstract

The problem of delivering payload in the form of a descent capsule using an orbital tether system is discussed in the paper. The dynamic law of controlling the deployment of an orbital tether system in the form of time dependence of the tether tension force is considered. It is shown that if a previously obtained optimal (relay) program of controlling the tether tension force is implemented the speed of tether deployment can reach high values. To reduce the speed of tether deployment a program of controlling the deployment of an orbital tether system, with prescribed limitations on tether deployment speed is obtained. Numerical simulation of orbital tether system deployment is carried out for the program of controlling the tether tension force with limitations on tether deployment speed. It is established that introducing too tight limitations on the speed of tether deployment does not make it possible to deliver the payload – a descent capsule - to the Earth surface. The dispersion of the points of landing of the capsule on the Earth surface caused by introducing limitations on tether deployment speed is analyzed

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):49-57
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Flight development tests and attempted operation of «AIST» small satellites
Kirilin A.N., Tkachenko S.I., Salmin V.V., Semkin N.D., Papkov A.P., Abrashkin V.I., Tkachenko I.S., Zheleznov Y.E., Galaeva E.Y.
Abstract

Small satellites «AIST» is a joint project of Samara State Aerospace University and Space Rocket Centre «Progress» (till 01.07.2014 – State research and production space-rocket center «TsSKB-Progress») with the support of the Government of the Samara region. The paper presents the results of flight development tests and operation of small satellites designed for scientific and educational purposes. Telemetric information on the operability of the small satellites' support systems and the data of the scientific equipment obtained from the orbit is analyzed. Possibilities of further use of «AIST» small satellites for scientific and educational purposes are considered.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):58-71
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Optimization of spatial turns of «AIST-2» small spacecraft on the basis of the principle of minimum control
Petrishchev V.F., Shipov M.G.
Abstract

The efficiency of using the principle of minimum control in solving the task of synthesizing the system of controlling a spacecraft spatial turn by arbitrarily set angles up to 180 degrees is analyzed, with the “Aist-2” small spacecraft taken as an example. The tensor of inertia has the form of a diagonal matrix. Flywheels the rotors of which are parallel to the principal central axes of the spacecraft inertia are used as actuating devices of the system that controls motion round the center of masses. The control moment developed by each flywheel, is proportional to the angular acceleration of its rotor. The energy spent on the control, proportional to the sum of modules of angular accelerations of flywheel rotors is accepted as an index of the optimality of the spacecraft spatial turn. Euler dynamic equations are reduced to finite-difference recurrent relations to model unperturbed spacecraft motion around the center of masses. An auxiliary dynamic system is introduced the parameters of which are chosen on the basis of the solution of the task posed to use the principle of minimum control that ensures minimum costs of control. The results of mathematical modeling confirmed the efficiency of the proposed principle. In comparison with the traditional method of control (acceleration, motion at a constant angular velocity, braking) two-fold economy of electrical power is achieved.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):72-79
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Stochastic optimal integration of hub airport technological resources
Romanenko V.A.
Abstract

The problem of defining the optimum structure and number of sets of airport technological resources intended for the performance of an individual operation of aircraft servicing and its loading is solved in a stochastic setting. The peculiarities of aircraft flows of a hub airport and strict requirements imposed upon the quality of hub airport ground service are considered. The maximum of the parameter that characterizes the efficiency of a set of resources is chosen as the optimality criterion. Limits are imposed on the productivity levels of the set and the quality of its ground handling operations. The approach that made it possible to establish the connection between the constraint parameters is described. The optimization problem is reduced to a stochastic programming problem that can be solved by methods of numerical probabilistic analysis. The solution of the problem of integration of resources of a hub airport’s functional subsystem intended for refueling airplanes is presented as an illustration. The results of the solution testify to essential influence of the stochastic character of airport processes on optimum characteristics of sets of technological resources.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):80-91
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Control of in-plane orbit parameters of a geostationary low-thrust satellite
Salmin V.V., Chetverikov A.S.
Abstract

The article focuses on the development of algorithms for controlling the parameters of the orbit of a geostationary satellite with the help of a low- thrust engine. We consider only the control of two-dimensional parameters that define the position of the satellite in the orbital plane, namely, the orbit time, the eccentricity and the point longitude of satellite observation. A two-dimensional problem of geostationary spacecraft terminal control is formulated. It is assumed that the correction maneuver is carried out by creating low transversal acceleration with the help of low-thrust electric propulsion, and the control vector consists of a sequence of durations of powered and unpowered portions. In this regard, the two-dimensional terminal control problem is solved in a discrete setting. For this purpose, a discrete model of the motion of a geostationary spacecraft in the orbital plane under the influence of low transversal acceleration is developed. It is quite difficult to solve the problem posed by using the traditional method of dynamic programming based on the use of the Bellman equation since the resulting discrete model of the satellite motion is a non-linear system of equations. Therefore, an approximate pattern of solving the problem on the basis of a three-step algorithm of the terminal control of the orbit time, eccentricity and point longitude of satellite observation is proposed in the paper. As a result, the plane terminal control problem is solved in an analytical form. Analytical expressions for estimating the costs of characteristic velocity correction maneuver using a three-step algorithm of terminal control are obtained. In modeling the motion of a geostationary satellite under the influence of low transversal acceleration the algorithm showed sufficiently high accuracy.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):92-101
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MECHANICAL ENGINEERING AND POWER ENGINEERING
Analysis of temperature fields of aircraft components
Azarenkov V.I.
Abstract

The problem of analyzing of temperature fields of aircraft components is central for ensuring the operational reliability of the latter. The results of developing methods of calculating temperature fields of the existing products and those being designed based on analytical solution of thermal conductivity equations for the principal types of structures are outlined in the paper. The thermal conductivity equation for a parallelepiped and cylinder with heat sources of a similar form is solved using the variable separation method. A common expression of the solution of thermal conductivity equation for bodies of the simplest form ( parallelepiped,  cylinder or its segment,  sphere or its segment) with spatial, flat, linear or point heat sources is obtained. A mathematical model for the analysis of thermal fields of aircraft components is proposed. Mathematical and thermal models are developed for the analysis of temperature fields of onboard REA. 

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):102-109
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Study of characteristics of the vortex throttling valve for the sysytem of water sample conditioning
Gimadiev A.G., Utkin A.V.
Abstract

Theoretical and experimental studies of characteristics of the vortex throttling valve (diode) for steam and water sample conditioning systems are discussed in the paper. Numerical simulation of forward and reverse flows in the vortex throttle channel is carried out with the help of the Ansys CFX software. Flow visualization, flow parameter field distribution, flow rate vs. pressure drop characteristics are obtained. The design characteristics of the throttling valve are consistent with the experimental results with an accuracy of 10%. Geometric parameters of the throttling valve are selected on the basis of a series of calculations to ensure reliable operation of the sample conditioning system.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):110-117
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Estimation of residual stress influence on the low-cycle fatigue of threaded parts
Zlobin A.S.
Abstract

The possibility of using the criterion of average integral residual stresses to estimate the cyclic life of threaded parts in the area of low-cycle fatigue is examined in the article. The peculiarities of fracture under high-cycle and low-cycle stresses are pointed out. The problems of using equations and criteria of linear mechanics in the low-cycle fatigue area are specified. These problems are mostly related to the origination of plastic deformation regions; the sizes of the latter may be significantly greater than those of the cracks. Technological factors affecting the origination and distribution of residual stresses are considered. It is noted that the diameter of the workpiece for thread rolling, heat treatment, the force and time of rolling are of the greatest importance.  The connection between the number of cycles prior to fracture and the residual stress value, expressed in terms of the average integral residual stress criterion under the influence of different technological factors is illustrated. According to the results of low-cycle fatigue tests of threaded parts it has been shown that the dependence of the number of cycles prior to fracture on the value of the average integral residual stress criterion is approximated closely by equations of the quadratic form. The appropriate magnitudes of approximation reliability are not lower than 0.9163.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):118-125
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Investigation of the causes of crack origination in the inner casing of NK-86 gas turbine engine combustion chamber
Kocherova Е.Е.
Abstract

The performance reliability of aerospace products is directly related to the reliability of each essential part; therefore special attention is paid to establishing the reasons of occurrence of defects and to developing preventive measures during the whole life cycle of a product. The article contains the analysis of the results of investigating the causes of defects occurring in the inner casing of the combustion chamber of NK- 86 gas turbine engine «Meridional cracks on the conical part of the flange». Metallurgical properties of the defective casing are examined in detail. A number of studies aimed at determining residual stresses on the surface of a part of the housing, as well as on specimens cut out from the housings with different hours in service and different surface treatment, including the use of additional thermal and mechanical treatment has been carried out. Diagrams of residual stress distribution for the specimens cut out of the housings with different treatment and subjected to various methods of relieving tensile residual stresses are presented. Endurance tests of one of the housings have been carried out. Conclusions about the influence of residual stresses on the fatigue resistance of the parts under investigation have been made. Measures to eliminate and prevent the defect both for the tested housing of the combustion chamber and for the base members manufactured by similar technologies and operated in similar conditions are proposed.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):126-134
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The influence of 3g and 4g vibration on the disperse structure of low-frequency and medium-frequency oscillation
Levkin Y.S., Lushkin I.A.
Abstract

The paper is devoted to experiments carried out on the DEVS– 200 A – 1 stationary testing bench that resulted in changes of hydrodynamic processes in the disperse structure under the influence of lateral vibration. The influence of vibration parameters (frequency of vibration and vibration accelerations) changes the structural model of two-phase flows. A classical two-phase structure wherein the whole surface of the elastic tube is caught in the field of lateral vibration is in its initial state prior to a certain threshold of vibration acceleration. The work is not concerned with the problems of structural changes. Two-dimensional graphs show the dependence of hydraulic parameters in the field of vibration influences. Three-dimensional spatial models characterize interdependence between three hydraulic parameters acted upon by vibration processes. Four schedules and two nomograms characterizing the obviousness of hydrodynamic dependences on the influences of vibration on them are presented.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):135-142
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Investigation of preliminary surface rolling influence on the fatigue resistance of threaded specimens
Sazanov V.P.
Abstract

The influence of preliminary surface plastic deformation on the endurance limit of parts made of steels 40X and 30ХГСА with the thread М16х2 has been examined. The investigation has been carried out by the computational-experimental method using the results of determining residual stresses mechanically on the specimens cut out of smooth workpieces and by modeling threaded specimens using finite-elements models. The method of thermal elasticity has been used for the calculation of the strain-stress state in the PATRAN/NASTRAN environment, whereby the distribution of initial deformations in the hardened layer is replaced by the appropriate temperature field. The graphs of distribution of axial residual stresses across the thread roots are plotted on the basis of the calculation. The increment of the endurance limit for threaded parts has been predicted by the average integral residual stress criterion. The calculation results are compared with the experimental data of testing the specimens. The specimens made of 30ХГСА steel without a nut were tested under the symmetrical cycle according to the pure bending pattern, the specimens made of 40X steel with a nut were tested under the zero-to-tension positive cycle in the case of stretching. Non-propagating fatigue cracks have been found in the specimens that withstood the tests and were destroyed.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):143-150
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Simulation of wire manufacturing production cycle
Haymovich I.N., Skripachyov D.G., Kolesnikova S.Y.
Abstract

The production cycle of manufacturing FLRY-25-Cc wire is analyzed making use of the work place photos obtained by measuring the time spent on each operation. A comprehensive account of the peculiarities of each operation the cycle consists of is proposed in the paper. It will help to optimize the production cycle. A model of the production process of wire manufacturing is constructed using a professional computational simulation tool Any Logic, which makes it possible to assess the impact of changes in various parameters of the system on the course of the production process.  Shortcomings in the organization of production of wires associated with irrational use of the equipment available, production cycle operations, logistics and product awareness of staff are revealed. Measures to optimize the production cycle of wire manufacturing are proposed that give a 40% increase of production efficiency.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):151-155
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Relationship between carbon concentration in a fuel and characteristics of flame propagation with a magnitude of ion current
Shaykin A.P., Budaev S.I., Galiev I.R.
Abstract

The practicability of using ionization probes for the investigation of fuel consumption in a piston engine is proved in the paper. It is shown that in order to expand the functionality, to increase the reliability of operation and accuracy of the processing of the ionization probe signal it is essential to know the influence of the fuel chemical composition and characteristics of turbulent flame propagation (velocity and width). In this connection, the paper presents theoretical and experimental research of the influence of turbulent flame propagation velocity, the width of the turbulent burning zone, the composition of the fuel-air mixture and the content of carbon in it on the indications of the ionization probe – the ion current. The work carried out resulted in obtaining functional dependence of ion current on carbon concentration in the fuel and characteristics of turbulent flame propagation. Experiments on the engine showed that if the excess air factor is in the range of 0.8 to 1.1 the agreement between the design and experimental values of the ion current in the first and second phases of combustion is over 83 per cent. The results of the work can be used to predict and monitor the propagation velocity and the width of the turbulent flame front in the combustion chamber of an internal combustion engine with the help of an ionization probe.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):156-163
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ELECTRONICS, MEASURING EQUIPMENT, RADIO ENGINEERING AND COMMUNICATION
A model of charging microparticles by discharge plasma with account for the electrostatic field
Semkin N.D., Vidmanov A.S.
Abstract

The discharge mechanism of charging microparticles in the charge case of the injector of an electrostatic accelerator is analyzed. The processes of origination and spread of the plasma discharge that occurs as the microparticle approaches the charging electrode are discussed. To determine the charge of the particles obtained as a result of microdischarge the problem of expansion of multi-component plasma under the influence of an electrostatic field is solved. A system of equations that describe the dynamics of the expanding plasma bunch, ionization and recombination processes, taking into account the influence of the electrostatic field on the plasmoid surface current, is solved. The described system of differential equations makes it possible to find the degree of ionization of chemical elements contained in the plasma bunch and the amount of ions as a function of time and chemical composition. The dependences of the degree of ionization of ions on the composition of the plasma bunch and the voltage on the charging electrode are obtained. The dependence of the particle charge on the voltage of the needle electrode is shown.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):164-170
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Methods and means of accelerating particles of natural and technogenic origin
Semkin N.D., Sukhachev K.I., Dorofeev A.S.
Abstract

Various types of accelerators of solid particulates of natural and technogenic origin are analyzed in the paper. We consider the structure and principles of operation of micron- and millimeter-scale accelerators with the center of velocity distribution of about 20 km/s: electrostatic, electromagnetic, pulsed, rail electromagnetic, solenoid coil and electric-gas dynamics, combined installations. Light-gas, explosive, gas discharge and electromagnetic accelerators with different principles of action are reviewed. The focus is on the electromagnetic techniques of acceleration that are most promising for acceleration of macrobodies to supervelocities. The advantages and disadvantages of different types of accelerators of solids are pointed out. The usability of different designs of accelerators to simulate collisions of orbital meteorite particles and space debris with the surface of the spacecraft is analyzed. Problems emerging in the construction and operation of accelerators of various types are specified and solutions to these problems are presented. The results of experiments in the acceleration of solid micron- and millimeter-wave solids using accelerators of various types and methods of structural optimization of particle accelerators with a view to increasing their efficiency and the speed of the accelerated body are presented. The evolution of accelerators and the main directions of their further improvement are shown.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):171-191
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Research of a pulse wave sphygmographic transducer
Fedotov A.A., Akulova A.S.
Abstract

The article discusses the structure of a pulse wave measuring transducer based on compression sphygmography. Practical examinations of an experimental model of the proposed measuring transducer have been carried out, involving 45 volunteers. The optimal value of the pressure injected  in the compression cuff in the range of 80 – 120 mmHg and the dynamic range of pulse wave amplitude  of 20 dB have been specified. Mathematical models of pulse wave signals and respiratory interference are used to determine the optimal parameters of the high-pass digital filter and the cut-off frequency of the high-pass analog filter. In the course of metrological research of the developed transducer the instrumental error in measuring amplitude-time characteristics of the pulse wave has been specified. It does not exceed 1.5% for the measurement of interpulse intervals’ duration and 2.3% for the measurement of the amplitude.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2015;14(4):192-199
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