Vol 16, No 1 (2017)

Full Issue

AIRCRAFT AND SPACE ROCKET ENGINEERING
Optimization of parameters of a hub aircraft ground handling system on the basis of a fuzzy-controller simulation model
Vasileva I.A., Romanenko V.A., Khvostova T.V.
Abstract

The paper deals with the problem of determining the optimum amount of technological resources of a hub functional subsystem, performing ground handling of aircraft (AC) for purposes of a chosen process step. A simulation model is proposed to be used for the optimization. The simulation model takes into account the peculiarities of the hub work activity and includes a fuzzy controller (FC) that reflects the logic of the airport controller who manages the process of aircraft ground handling. A model example of the solution of an optimization problem is presented. The example indicates the possibility and feasibility of using a fuzzy controller to model a human operator’s strategy.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):7-19
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Information control system for space experiments onboard international space station
Voronin F.A., Dunaeva I.V.
Abstract

The paper considers development of the Information Control System (ICS) of the Russian Segment of the International Space Station (ISS). The main ICS modules for carrying out scientific experiments comprise the Service Module, the Multipurpose Laboratory Module and the Science Power Module. At present specialists of “Energia” RSC are working to create high-tech conditions for scientific experiments on the new ISS modules, modernize the existing ones and combine them into a single onboard ISS information control complex. The information control system (ICS) is intended for automatic and manual control of space experiments. The effectiveness of modernization was confirmed by the results obtained during space experiments on the basis of the Information Control System. The ICS modernization started in 2012. At that time the ICS consisted of 4 onboard computers. The main task of ICS modernization was to introduce new computers and software-hardware systems. The software was supposed to have a flexible architecture and provide resources for all future onboard payloads. At the first stage one onboard computer was replaced. The main purpose of that stage was to test the new ISS hardware and software. The rest of the ICS computers will be replaced at the second stage, the Multipurpose Laboratory Module and the Science Power Module will also be equipped. The reliability of the system hardware is improved using functional backup. In 2014 2 cameras were installed on the ISS together with UrtheCast company (Canada).One of the cameras is a middle resolution camera; the other one is a high resolution camera. Today ground preparation of an experiment with “Icarus” scientific equipment is being carried out, jointly with the German Center of Aviation, DLR, and the SpaceTech company (Germany). The experience of the first stage of modernization suggests that the modernized ISS RS ICS will become an up-to-date system allowing the realization of most ambitious space experiments in automatic mode.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):20-30
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Analysis of the accuracy of autonomous navigation of the space robot in the diagnosis of the technical condition of an orbital object
Golyakov A.D., Fominov I.V., Korolev S.Y.
Abstract

The article presents the results of analysis of the accuracy of autonomous navigation of a space robot in solving  tasks of remote diagnostics of the technical condition of an orbital object in coplanar orbits. The angle between the stellar line and the direction of the orbital object, the distance to the orbital object and the rate of its change are taken as the primary navigation parameters measured onboard of a space robot. The space robot navigation accuracy is assessed on the basis of an analytical method. Assumptions of the normal law of distribution of measurement errors with known characteristics, the motion of the space robot and the orbital object in the central gravitational field of the Earth and the equality of the heights of their reference orbits are introduced. As a result of research covariance matrices of errors of determining the parameters of space robot center-of-mass motion were obtained in analytical form. The analysis of the accuracy of autonomous navigation carried out in the present paper can be used at the stage of feasibility study of the conceptual design of the control and navigation system of a space robot, for example, when solving the problem of choosing the composition of the onboard equipment, determining the accuracy specifications of onboard measuring devices and the amount of measurements carried out within the navigation mode.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):31-41
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Design and technical characteristics of transport airplane for arctic exploration
Kuprikov N.V., Dolgov O.S., Kuprikov M.Y., Ivanov B.V.
Abstract

The geographic location of the Russian Federation determines regional apartness of the Arctic and Far East territories which are mostly isolated. The necessity of development of the Russian North Polar regions calls for the development of transport infrastructure and specifies requirements to flight characteristics of regional airplanes, which requires new research and development solutions. Positioning the Arctic territory as an exclusive economic zone on the world political arena necessitates the development of the regional transport network including all-cargo and passenger services for sustainable development of the region. An up-to-date approach to aircraft design should be based on Arctic exploiation requirements, infrastructure-climate limitations and design methods that include methods of moment-inertia analysis, structural-parametric analysis of Arctic-based aircraft taking into account the choice of rational moment-inertia configuration. Synthesizing the limitations and required operation characteristics we designed an Arctic-based airplane that can perform transport operations in the Russian Arctic zone safely and successfully.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):42-50
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Improvement of gas turbine engines due to isothermal expansion in the turbine
Muraeva M.A., Gorjunov I.M.
Abstract

The article presents the results of the study of application of isothermal expansion in the turbine of gas turbine engines as a way of improving the thermodynamic cycle. We present equations of work and ideal cycle efficiency of a gas turbine engine with isothermal expansion in the turbine. We performed a comparative analysis of the cycle under consideration and the traditional cycle of a gas turbine engine with adiabatic expansion on the basis of the equations mentioned above. In order to carry out a thermodynamic study of real isothermal expansion in the turbine of a gas turbine engine on the basis of 3D numerical simulation we examined the turbine characteristics and determined corrections of an adiabatic- expansion turbine characteristics for isothermal expansion. By using the obtained correction data and characteristics, on the basis of the method formed, we investigated the use of isothermal expansion in gas turbine engines of various schemes based on thermodynamic calculation at a set point and calculation of altitude-speed performance. The studies prove the efficiency of using isothermal expansion as a way of improving the thermodynamic cycle of turbojet engines and turbofan engines with a low-bypass ratio, in particular with reference to supersonic military and civil aircraft.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):51-61
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Frequency characteristics of a coaxial gas damper for booster feed line
Odinokov D.A., Gimadiyev A.G.
Abstract

In development and maintenance of liquid rockets it is essential to ensure its stability in relation to longitudinal oscillations of the body (longitudinal stability, pogo effect) for all possible disturbances. It is known that one of the most effective ways to ensure the longitudinal stability is to use gas dampers-accumulators installed in the feed line at the engine inlet. The damper in the feed line produces additional compliance, thus making it possible to eliminate the coincidence of the fundamental natural frequency of the pressure fluctuations in the feed line and the natural frequencies of the rocket body, which is necessary for providing the longitudinal stability. The damper parameters are selected on the basis of mathematical modeling and experimental data. In this paper, a nonlinear mathematical model of a coaxial gas damper is developed with the use of the ideal-gas law equation for an adiabatic process and the Bernoulli and Saint-Venant – Vantsel equations. The mathematical model is used to calculate the frequency characteristics of the damper in the form of input acoustic conductance. The results obtained make it possible to take into account the contribution of passage sections of the throttles to the performance of the damper at the design stage, as well as to select its parameters in simulating processes in the feed lines to solve the longitudinal stability problem.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):62-74
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MECHANICAL ENGINEERING AND POWER ENGINEERING
Dynamics of feed water flow rate control system with low- noise regulator
Berestovitskiy E.G., Kizilov P.I., Kruchkov A.N., Pialov N.V.
Abstract

We present the results of modeling a feed water control system. The system contains two regulatory devices – the feed valve to control the flow rate, with electrohydraulic control, and the throttle valve to maintain constant pressure differential on the feed valve, with hydromechanical control. The valves have perforated flow parts to reduce hydrodynamic noise and vibration, which necessitates checking the dynamical characteristics of the system. The model was developed on the basis of equations describing the electrohydraulic converter dynamics, a differential pressure meter, a servo drive and flow parts with the use of Matlab Simulink. The modeling of dynamical processes caused by various disturbance inputs and control actions showed the compliance of the system with the requirements imposed on it.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):75-86
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Influence of assembly conditions on the stressed-stained state of damper support elastic rings
Diligensky D.S., Novikov D.K.
Abstract

The article considers the influence of different tolerance values on the stiffness of elastic rings in squeeze film dampers. This type of damper is widely used in gas turbine engine supports. The available analytical solutions have a number of limitations. A parametric finite-element model of an elastic ring, a set of two interconnected elastic rings and a simplified segment is presented. The results obtained show the discrepancy between values of compliance for different numerical models as compared to analytical approaches. The effect of assembly tolerances on the value of compliance is shown.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):87-100
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Prospective lines of improving the process of evaluating the technical condition of aircraft hydraulic system working fluid
Koptev A.N., Gareyev A.M., Popelnyuk I.A.
Abstract

The article is devoted to the evaluation of the technical condition of aircraft hydraulic system working fluids. Working fluid parameters (concentration of impurities, viscosity, density, anti-oxidation, anti-wear and thermal properties) determining its technical condition are selected on the basis of a study of scientific and technical literature. The peculiarities of the existing process of its evaluation are discussed. A structural grapho-analytical model reflecting the condition of the working fluid was developed. The model takes into account the influence of the fluid’s basic parameters as well as reachability and counter-reachability matrices. Analyzing the results, it was found that the graph components are strongly interconnected. Viscosity is closely linked with anti-wear and thermal properties, while variations in mechanical impurity content in the working fluid cause variations in the rest of its parameters. Thus, we can say that the assessment of the working fluid’s condition based on measuring only its purity and viscosity is not quite reliable. We substantiate the future line of research with the aim of developing new methods to assess the condition of the working fluid, namely, development of mathematical models of the working fluid condition taking all its components into account.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):101-108
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Types of aeroelastic vibrations of turbomachinery bladed discs
Koskin A.O., Seleznev V.G.
Abstract

A real process was analyzed for presence of self-oscillations. Absence of self-oscillations was revealed as its attributes such as progressive wave and beating were not discovered. A model of oscillatory process was proposed on the basis of the kind of oscillograms and the linear superposition theory for several simultaneously excited oscillation modes. In accordance with the theory two vibrations with frequencies equal to 919 and 469 Hz were summed up. As a result of addition of these frequencies and comparison of the derived oscillograms with the real process it was found that the proposed model agrees with the original well enough. Moving further into the process, a third frequency component equal to 1002 Hz originates in addition to those of 465 and 918 Hz. Addition of three frequencies carried out similarly to the first example also yields a satisfactory result. Oscillograms of real and model processes have a similar appearance. The frequency components calculated on the basis of the oscillogram of the model process practically coincided with the real process frequencies. Classification of aeroelastic oscillations was analyzed in order to determine the oscillatory type of the process under investigation. Three main phenomena were distinguished: forced oscillations, flutter and non-synchronous oscillations. Almost all foreign engine companies faced the latter phenomenon, sometimes mistaken for flutter. The analyzed example was labeled as non-synchronous oscillations according to features of non-synchronous oscillations, namely, aliquant rotation frequency and resonant behavior of oscillations.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):109-114
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Evaluation of low cycle fatigue based on the use of Coffin-Manson dependence under zero-to-“soft” loading cycle
Pavlov V.F., Kirpichyov V.A., Kocherova E.E., Zlobin A.S.
Abstract

To calculate the durability of gas turbine engine parts damaged by low-cycle fatigue (LCF), according to the “Structural codes of turbine engine strength” it is necessary to test specimens cut from respective parts (or test coupons) under “hard” loading. “Hard” here means there is a fixed strain cycle. The tests are conducted with different asymmetry coefficients of the strain cycle and with different exposure time at the maximum cycle strain (to take into account the effect of creep at high temperatures). The tests carried out are to provide sufficient statistics to ensure the reliability of the calculation. We suggest a method of assessing the durability of gas turbine engine parts based on testing standard specimens at zero-to-“soft loading” cycle using modified Manson-Coffin’s equation. The results of the work confirm the possibility of achieving the required adequacy of assessing the durability of parts damaged by the LCF mechanism with the use of a modified Manson-Coffin equation. Some recommendations concerning its application are given.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):129-136
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Mathematical models of squeeze film dampers in rotor dynamics of gas turbine engines
Kutakov M.N., Degtiarev S.A., Leontiev M.K.
Abstract

The paper focuses on the choice of mathematical models of squeeze film dampers and methods of their numerical implementations for gas turbine engine rotor dynamics problems. The present contribution is aimed at establishing criteria for the application of mathematical models of a squeeze film damper depending on the damper characteristics and operating conditions. The models are grouped by the dimension of the considered physical space, i.e. three-dimensional, two-dimensional and one-dimensional modeling patterns. The work presents principles of setting boundary conditions for mechanical seals to be adequately simulated. Criteria of assessing the necessity of taking into account such physical phenomena as turbulence, fluid inertia, and cavitation are presented. The proposed mathematical models are primarily developed for the computation of integral characteristics of squeeze film dampers, such as reaction forces and dynamic stiffness and damping coefficients required for solving rotor dynamics problems.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):115-128
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On the efficiency of a radiant heating regenerative system
Panchenko V.V.
Abstract

A scheme of a radiant heating regenerative system is developed on the basis of a two-flow heat generator, a system and form of heat-radiating air ducts is proposed. It is shown that the system of radiant heating is more efficient as compared to the conventional convection system. The climatic conditions in Samara Region make it necessary to provide heating of houses for at least 200 days a year. Traditionally, the convective scheme of heating is used wherein radiators installed near the floor are used. Water serves as the working fluid in the radiators. The proposed radiant heating regenerative system is based on the transfer of heat in the form of infrared electromagnetic radiation. Air acts as the working fluid in the system. A microclimate with the required level of moisture and content of oxygen is created inside closed premises. Ways of using the systems described are suggested and recommendations on the necessity of conducting further research are given.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):137-141
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Selection of reference specimens for assessing the efficiency of part surface nitriding
Sazanov V.V.
Abstract

The use of corset reference specimens for carrying out fatigue tests and smooth reference specimens for determining residual stresses in a surface layer to assess the sufficiency of nitriding (thermochemical processing) is substantiated in the paper. The calculations are carried out by finite element simulation using the ANSYS and PATRAN/NASTRAN software complexes. The ANSYS complex is used to determine the stress concentration factor for the case of corset specimen bending. The employed models with harmonic axisymmetric finite elements make it possible to find the stress concentration factors in the case of tension- and- compression and bending of body-of-rotation parts. The obtained value of the influence of the coefficient of residual stresses on the endurance limit increase is in quite good agreement with its experimental values for nitriding and other types of thermochemical treatment of corset specimens. The PATRAN/NASTRAN complex is used to calculate the stress-strain state in corset specimens depending on residual stresses arising on a part surface under nitriding. Modeling is performed by the thermoelasticity method, with experimental diagrams of residual stresses in smooth specimens used as initial data. It is established that the distribution of axial residual stresses in the dangerous (smallest) section of a corset specimen practically does not differ from the distribution in smooth specimens. The results obtained provide the basis for determining average integral residual stresses by the distribution of residual stresses in smooth specimens and using them to calculate the endurance limit for hardened corset specimens. The results of the study allow making a conclusion that the most optimal nitriding practices are those wherein the average integral residual stresses are maximal. 

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):142-151
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Safety front shock damper (shock absorber) to protect containers in emergency falling
Samokhin P.A., Bakhareva E.A., Potanin D.V.
Abstract

The article presents a front shock damper (shock absorber) for protecting containers with flying machines against fractures in case of emergency falling in the process of transportation and operation. Two numerical methods are proposed to calculate the stress-strain state and acceleration braking of a shock absorber in case of a vertical fall and impact with a stationary concrete surface. The methods are based on the use of ANSYS Workbench 16.1. The first technique consists in determining the stress-strain state on the assumption of quasi-static loads. The second, dynamical, method makes it possible to determine the reaction of a shock absorber to its impact with the concrete surface depending on time. What makes our technique special is that we take into account plastic properties of a material and actual contacts between the damper components. The methods proposed are validated by the analytical solution of the differential equation of container motion with the shock absorber in the elastic strain range. The methods are illustrated by an example of calculating a given damper. The results obtained by three methods show quite good agreement taking into account the calculation error. It is established that the energy of the shock absorber plastic-elastic strain upon an impact is more than half of the kinetic energy of the shock absorber in motion. The dependence of the shock-absorber braking acceleration both on the size of the crumpled area and on the time is determined.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):152-161
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Dynamics of the hydromechanical system of a production machine with an adaptive tool-feeding drive
Sidorenko V.S., Poleshkin M.S., Rakulenko S.V.
Abstract

The article investigates a hydro-mechanical system of regular feed and principal movement of a production machine (as illustrated by a mobile drilling rig).We study the behavior of a dynamic hydro-mechanical system under varying external processes of well drilling. The task of maintaining the optimal drilling process is solved by using an original design (multivariate sensor, additional hydraulic lines linking the principal movement and the tool-feeding movement). Travel time characteristics and dynamic behavior of the regular feed are provided with one power plant. A dual-mass mathematical model of a dynamic multi-mass hydro-mechanical system (MHS) is proposed in Matlab Simulink software environment. The model contains an analytical description of mechanical, hydraulic and control subsystems and is implemented by subsequent complications of the basic model starting from a single-mass linear model to a nonlinear dual- mass one with active submodels of all subsystems. The application of the model makes it possible to study the duty cycle of a multi-branch MHS, while maintaining the consistency of the results of solutions that are getting increasingly complicated.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):162-175
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Influence of crack depth on the stress intensity coefficient in notched and smooth plates
Surgutanov N.A.
Abstract

The paper presents an analysis of variations in the stress intensity coefficient (SIC) in plates with different sizes of the cross-section, with and without concentrators. We also analyze the dependence of the SIC maximal value on the size of the smallest section of a plate with stress concentrator.  SIC of smooth specimens and specimens with stress concentrator in the form of a semicircular notch are calculated using the ANSYS finite- element analysis program system. The static elastic problem is solved, with the strained state taken to be biaxial. The material of the plate is considered to be isotropic. The plates under consideration with a concentrator in the initial area of the crack size increase show maximum stress intensity coefficient. In plates without concentrator the SIC changes smoothly over the whole area of the crack size increase. It is established that the crack size is equal to 0.02 of the plate smallest size at the maximal value of the stress intensity coefficient. The study conducted confirms the feasibility of using the criterion of average integral residual stresses to calculate the increase of the endurance limit of surface- hardened specimens and parts with concentrators due to compressive residual stresses.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2017;16(1):176-185
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