Vol 16, No 2 (2017)

Full Issue

AIRCRAFT AND SPACE ROCKET ENGINEERING
Control over the deployment of an orbital tether system of great length
Wang C., Zabolotnov Y.M.
Abstract

Control of deploying an extended tether system into the vertical position is considered in the paper. It is assumed that in the initial state the system consisting of two space vehicles moves in a circular Earth orbit. We propose nominal control programs ensuring the deployment of the system to a predetermined length and taking into account the restrictions on the speed of tether and force in the control mechanism. To construct nominal deployment programs a mathematical model of the system’s motion in the orbital moving coordinate system is used. The model takes into account the peculiarities of the problem. We assess the operability of the proposed programs of deployment according to the mathematical model of controlled motion of the orbital tether system with distributed parameters recorded in the geocentric coordinate system. To perform test calculations a linear regulator that provides feedback on the length and speed of the tether deployment is used. 

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):7-17
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Formulas of reducing engine environmental performance and combustion characteristics to standard atmospheric conditions
Grigoriev A.V., Kosmatov A.A., Rudakov O.A., Solovieva A.V.
Abstract

The article specifies formulas of reducing environmental performance and combustion characteristics of a gas turbine engine, as well as its thermodynamic parameters to the standard atmospheric conditions, with flight altitude H = 0 and Mach number M = 0: p0= 760 mm Hg. (101.325 kPa), T0=288.15 K (+15°C), for which the engine technical assignment is specified. The atmospheric conditions determined by the air temperature, pressure and humidity vary over a wide range depending on the season, terrain elevation, and latitude. Therefore, reduction of engine characteristics to the standard atmospheric conditions is necessary and it is based on the similarity theory, i.e. on maintaining constant gas dynamic and geometrical criteria of the combustion chamber. An integral mathematical model of the combustion chamber forms the theoretical basis of the presented reduction method. It is grounded on the results of solving a system of differential equations describing heat, mass (concentration) and momentum transfer specified by the combustion chamber theory. The article shows a significant influence of the ambient air temperature on emission and fuel combustion characteristics as distinct from the influence of other atmospheric parameters.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):18-22
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Fluctuations of liquid fuel in tanks with oil recovery units
Dyachenko M.I., Duy Hung N., Temnov A.N.
Abstract

The article presents solutions of problems of natural fluctuations of liquid in cylindrical, conical and spherical tanks, with boundary conditions on the free surface and the surface with resistance, i.e. the drain surface. Particular attention is paid to finding the eigenvalues and eigenfrequencies of equations of oscillations of perturbed motion of fluid with the presence of dissipation on the boundary surfaces. It is shown that low speed of lowering of the free surface and resistance conditions on the surface of the drain can affect both the oscillatory and the aperiodic parts of the solution of the fluid oscillation problem.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):23-35
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Development and analysis of models of heat transfer in compact porous heat exchangers of aero space control systems
Konovalov D.A.
Abstract

The paper presents a study of thermal and hydraulic characteristics of porous heat exchangers in conditions of intensive heat dissipation from compact surfaces. We present a mathematical model of convective heat transfer in a porous heat exchange element for conjugate Darcy-Brinkman-Forchheimer equations with boundary conditions of the second kind. An accurate solution of hydrodynamic and thermal problems is obtained analytically by integral transformation. We obtained dependences for determining the velocity field, the length of the initial hydrodynamic area, the Fanning hydraulic friction head, the local temperature of the porous matrix and the liquid cooler, the local Nusselt numbers. We assessed the influence of porosity, permeability, Darcy and Reynolds numbers on the thermal and hydraulic condition of a compact porous heat exchanger. Reasonable ranges of thermal and hydraulic characteristics of the heat exchangers being developed are established. Critical operating modes of heat exchangers are specified. The data obtained agree well with the classical results. We developed an engineering methodology differing from the existing ones by its invariance. The methodology makes it possible to determine the design characteristics of compact porous heat-exchange elements of aerospace control systems.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):36-46
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Complex approach to aerodynamic design of inlet ducts with submerged vortex-free air intakes
Kornev A.V., Boychuk I.P.
Abstract

The paper shows the possibility of improving gas-dynamic characteristics of a submerged air intake and presents a technology of developing design solutions according to the principle of conformity to the flow lines. The gas-dynamic principle of shaping is provided by means of computer-aided integrated technologies of design and application of numerical visualization methods as design tools. The revealed regularity of the working process of the external streamline of the preceding airframe surfaces unambiguously defines the fundamental design distinctions of the conformal air intake in the form of the converging side edges on the stream and determines its advantages over the analogs.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):47-59
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Some issues of research and development in aviation industry
Korchak V.Y., Kuznetsov V.V., Borisenkov I.L., Leonovich G.I., Lukachev S.V., Biryuk V.V.
Abstract
The paper is devoted to some issues of ensuring the efficiency of research and development in the field of aviation industry. Special attention is given to the groundwork in the area of aircraft engine building. We specify the basic standard requirements to aircraft engines, their parts and components, logistic support; requirements to the processes of creating, manufacturing, conditions of operation and maintenance, overhaul, storing, disposal; leading standard technologies or those already implemented in aircraft items. We point out the key areas of activity: additive technologies and additive manufacturing – systems of producing/growing optimal material objects, first of all, 3D printing (selective laser sintering, fusion), infusion and PIM-technologies, methods of surface treatment, development of bionics and use of honeycomb or composite structures with an optimal microstructure; mathematical modeling and supercomputer engineering to optimize various characteristics and processes of additive manufacturing. 
VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):60-64
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Micro gas turbine engine imitation model
Kuznetsov A.V., Makaryants G.M.
Abstract

Benches are widely used in the process of creating automatic control systems (ACS) for gas turbine engines (GTE). The engine work is simulated via mathematical models. The model is supposed to be highly accurate in conditions of quite rapid calculation of the engine main parameters in both steady-state conditions and transient processes. A simulation model of a micro gas turbine Jet Cat P-60 engine is presented in the article. The model is based on the data obtained from generalized engine performance. A simulation model of a small-sized gas turbine engine is developed by plotting the rotor acceleration against the rotor rotational speed and the combustion chamber fuel consumption at each moment of time. The results of simulating the engine operation are compared with the experimental data obtained with increasing the GTE operation mode. The average modeling error value is obtained: 1.04% (ambient temperature is 288 K), 2.58% (249 K). It is acceptable for an adequate simulation of the GTE bench performance.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):65-74
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Criterion assessment of the possibility to prolong the service life limit of the helicopter tail drive shaft
Mashoshin O.F., Semenikhin R.L.
Abstract

Low life time of home-produced helicopter transmission elements in comparison with foreign analogues is one of the problems of Russian helicopter industry. For example, the service life limit of Mi-2 drive shaft is 4,500 hours, the time between overhauls is 1,500 hours. The time between overhauls for the drive shaft of a similar helicopter Bell 429 is 3200 hours, for the Eurocopter AS350 it is 3000 hours. The service life limit of the drive shafts of Bell 429 and Eurocopter AS350 is not specified. As the financing of operations to prolong the service life limit of high-load elements of aircraft structure is very limited it is necessary to suggest other, less labor-intensive ways of assessing the technical condition of these elements in order to prolong the service life limit. New criteria need to be introduced to solve this problem. New criteria for the assessment of the possibility of prolonging the assigned life of helicopter tail rotor drive shafts are proposed and scientifically justified in this article. The criteria indicate changes in chemical, physical and mechanical properties, as well as strength properties of products after some time of service. Comparing the properties with their maximum values we can make a conclusion about the possibility to prolong the life cycle of helicopter transmission components. An example of the criteria calculation for the Mi-2 helicopter tail drive shaft with an expired Service Life Limit of 4500 hours is given.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):75-80
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Mathematical modeling of a controlled electromechanical actuator for special assembly and coupling equipment
Nosov A.S.
Abstract

The article presents theoretical and experimental bases for the creation of a driving gear with an actuating mechanism based on a planetary roller drive to improve the fidelity of the specified motion law and velocity performance of the support equipment actuators and engineering systems of missile and space-rocket complexes, as well as for integrated tests of heavy missiles. We present a mathematical model of a controlled electromechanical actuator for special assembly and coupling equipment. The results of the tests carried out lead to the conclusion that in order to create a high precision electromechanical drive, it is necessary to use transmission with a smaller gap between the mating elements, high accuracy and reliability of operation. A new design of a planetary roller drive and the advantages of using a stepper motor are described. Thus, mathematical modeling of an electromechanical actuator with a planetary roller drive with a mockup test on an assembly and coupling tilting device makes it possible to create an electromechanical actuator with improved technical and operational characteristics for a  tilting device of the space head of a super heavy launch vehicle. This reduces the probability of emergency situations during conducting government and commercial space programs.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):81-89
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Assessment of gas turbine engine airfoil surface microstructure
Nosov N.V., Abramov A.D., Kosulin S.I.
Abstract

We propose a new approach to the assessment of surface roughness of gas turbine engine airfoil after polishing. The micro-geometry of the blade surfaces was investigated with the use of an electrooptical system on the basis of computing the average amplitude of the variable component of the autocorrelation function obtained as a result of computer processing of the surface video images. The use of the electrooptical method of assessing the surface micro-geometry of compressor blades and turbine blades makes it possible to construct the fields of surface roughness and stress concentration factor, as well as to analyze the technology of finishing treatment in more depth.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):90-100
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Application of Bubnov-Galerkin method to determine fixed vibrational loads of launch vehicle compartments
Popov P.A., Sindyukov A.A., Malykhina O.I.
Abstract

The stage of qualification vibration tests of space rocketry products is one of the most important stages of their design. To carry out the tests it is necessary to know the levels of vibration loads as early as the system definition stage. It is necessary to use methods that were previously tried and found efficient when defining the modes of vibration and acoustic loading on the structural elements of advanced launch vehicles and the assembly and protective blocks. The results of calculations made according to efficient methods in most cases agree with the results of full-scale measurements. We propose a methodological complex that will help engineers to create necessary vibration dynamic impact on the structures of space-rocketry products. Equations of shell vibration dynamics and a way of solving them on the basis of Bubnov-Galerkin method is presented in the paper. A method of forming the right-hand sides of the equations is also presented. The equations under consideration are equivalent to the actual spectra of external acoustic loads determined at the stage of flight development tests. A way of forming frequency-dependent damping characteristics of the structure is described. Spectral characteristics of vibration dynamic impact on a launch vehicle of the “Soyuz” type obtained by the results of processing of telemetric information are given. The vibration dynamic impact on the structure of the launch vehicle compartments is calculated on the basis of the characteristics specified. The results of the probability analysis of the vibration loads obtained are presented.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):101-110
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Multi-purpose high-precision thermal vacuum testing bench and someresults of firing tests of non-hypergolic low-thrust rocket engines
Ryzhkov V.V., Verjasov Y.N., Galperin R.N., Gulyaev Y.I., Ivashin Y.S.
Abstract

The article presents the structure and the main characteristics of systems of a multi-purpose thermal high-precision testing bench for firing tests of non-hypergolic low-thrust rocket engines (LTRE). The vacuum system provides the initial vacuum in the chamber; the fuel system makes it possible to conduct research and tests of LTRE with the thrust 5...500 N in continuous and pulse modes of operation. The thermal conditioning system creates and maintains the temperature of the fuel components in the range from -15 to +50°C at the inlet of the engine. The thermostats ensure a minimum temperature of gaseous working fluids ~ 100...120 K during tests conducted according to special programs. An automatic system of control, acquisition, handling and displaying of the measurement information is intended to support research and testing of rocket engines and to obtain real-time results. The measuring system is equipped with high-precision sensors that significantly increase the accuracy of the LTRE parameters to be determined. An infrared thermal imaging system makes it possible to assess the thermal state of the engine. The results of experimental research of the work process of non-hypergolic rocket engines are presented. We also present information on the dynamic and energy parameters of promising schemes of LTRE using the components Н2г + О2г, and on the thermal condition of the engine structure.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):111-126
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Assessment of a liquid rocket engine concept based on innovative technologies
Solodovnikov A.V., Akinshin I.A., Golubyatnik V.V., Krivonogov A.V.
Abstract

Application of innovative methods of production such as additive technologies and use of composite materials in the engine primary structure is one of the promising directions of reducing the cost of production of liquid rocket engines. The purpose of the work is to assess an innovative engine concept   with the mixing head made by an additive technology and the cylinder and nozzle made of a composite material. To solve the main tasks of the investigation we analyzed the available experience in introducing innovation production methods into aerospace engineering. A feasibility study of configurations of separate components manufactured by method of additive and traditional technologies was performed. According to the results of the validation firing of the model the operability of the new configuration was confirmed and the main engineering problems to be solved were determined. The results of the analysis of the innovation engine concept show a 3- or 4-fold reduction of labor intensity in serial production, as well as 3-6-fold reduction of the components variety required for a single assembly. In addition, it is necessary to note the 25% reduction of the item mass. The design modification makes it possible to provide the augmentation of engine operation up to 30% of nominal thrust.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):127-134
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Investigation of the thermal regime of microsatellite optoelectronic telescopic complex under operating conditions
Tsaplin S.V., Bolychev S.A.
Abstract

An optoelectronic telescopic lens-type complex is proposed for the purpose of creating a domestic constellation of Earth remote sensing satellites with the ability of timely obtaining of the imagery on-demand. A thermal control system based on electric heaters was chosen to maintain the optimal thermal conditions of the lens telescope. The calculation of the objective’s thermal mode was carried out on the basis of a 3D model taking into account actual operational conditions of the spacecraft in its orbital motion. The dynamics of the transient temperature fields of the objective was calculated using the finite- element method under various operating conditions of the microsatellite: stabilization of the thermal regime, Earth remote sensing, emergency failure of the heaters. It is shown that the thermal control system maintains a predetermined temperature range of the optical elements under nominal operating conditions with moderate energy consumption.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):135-144
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MECHANICAL ENGINEERING AND POWER ENGINEERING
Numerical method of determining creep model parameters within the first two stages of creep
Zoteev V.E., Makarov R.Y.
Abstract

The article describes a new numerical method for determining the parameters of a creep model within the first two stages of creep. The numerical method is based on the transition from a nonlinear model of creep to a linear-parametric discrete model. The linear-parametric discrete model describes the sequence of experimental values of creep deformation. The formulas describing the relationship between the coefficients of the linear parametric discrete model and the parameters of the reference creep model are presented. We propose an iterative procedure of RMS estimation of the coefficients of the linear parametric discrete model. The developed numerical method was tested in the estimation of parameters of a creep model, and the validity of the relationships obtained was confirmed.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):145-156
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New technologies of manufacturing non-rigid parts made of titanium alloys and stainless steels
Kiselev E.S., Blagovskiy O.V.
Abstract

The article considers a new approach to solving a topical scientific problem of providing dimensional stabilization of non-rigid aircraft parts made of titanium alloys and stainless steels. It is known that a significant loss of accuracy and a change in the spatial orientation of surfaces of non-rigid parts are associated with the formation of undesirable technological residual stresses in the surface layers. The authors of the work propose a method of reducing the magnitude of residual stresses in the surface layer of cylindrical parts by ultrasonic treatment with an indenter having strip contact with the workpiece. We present the results of experimental research aimed at eliminating the lengthy operation of thermal relaxation of residual stresses in the process of manufacturing non-rigid parts made of titanium alloys and stainless steels through the rational use of technological heredity phenomena and ultrasonic field energy. The developed method is highly efficient and can be used to stabilize dimensional accuracy of non-rigid and thin-walled parts made of hard-to-machine materials.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):157-163
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Numerical modeling and experimental research of a two-phase liquid- gas ejector with a profiled supersonic nozzle
Lepeshinsky I.A., Reshetnikov V.A., Zarankevich I.A.
Abstract

A two-phase liquid-gas ejector with a supersonic nozzle is described in the article. The results of numerical modeling of the processes occurring in it and forming a two-phase jet are presented. The structure of a two-phase flow formed by the ejector and the velocity field of the dispersed phase are experimentally investigated. The characteristic curves of the ejected gas flow for different values of the working fluid consumption are obtained and the rarefaction achieved by the ejector is measured. The ejector ensures the system’s operation that forms two-phase high-concentration gas-droplet jets at different flow rates and pressures of working bodies. It is established that, due to the presence of air in a two-phase working body, a two-phase jet at the exit from the ejector accelerates in the initial section and then is decelerated. The results of the numerical modeling of internal processes occurring in a two-phase liquid-gas ejector are presented in fluid and gas dynamics ANSYS software application packages on the basis of analyzing a small-scale model. The characteristics of the energy efficiency of a full-size jet device are given, as compared to production prototypes. The prospects of using liquid-gas jet devices for high-altitude testing of jet engines and their units are indicated.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):164-171
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Method and algorithm of decomposition for the synthesis of programs of control of electrical equipment complex objects
Myasnikova J.V.
Abstract

The article considers dimension problems of electrical equipment complex objects in developing test programs in the context of programming diagnostic tasks. To solve the problem, we propose a method and an algorithm for the effective description of electrical equipment objects for its decomposition, i.e. reducing large-dimensional problems to the solution of a number of simpler problems. An adequate task description language based on the theory of graphs was chosen for solving dimension problems. To represent the results, we use the concepts of U. Grenander’s patterns theory. To solve the problems of synthesis (design) and analysis we use a single methodology of pattern representation using models of their components, circuits (configurations) made up of them and images of production objects. The decomposition method is based on the analysis of the controlled object in the context of the graph theory and the separation of strong components in the matrices of the electrical connections of the elements. The scheme is divided into separate functional modules, each module including a functionally complete part of the scheme that forms the basis of designing tests for discrete circuits of objects.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(2):172-182
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