bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies to harness Bengaluru’s solar potential
Authors: Thanikonda Ashok , Krishnan Deepak
Published: May 2017

Solar energy is a key component of cities’ climate mitigation and energy security plans, due to its ease of installation & operation and drastic decline in costs.In Bengaluru, residential, commercial and industrial (C & I) consumers contributed to around 85% of the electricity consumption and resultant emissions during 2014 and 2015. What are the options for these consumers within the ambit of current policies to procure solar power? Are changes required in these policies to scale up the adoption of solar power?WRI India has explored two possible options – off-site and on-site procurement of solar energy.On-site procurementIn 2013, net-metering which allows export of excess power to the grid was not available in Bengaluru. This, in addition to expensive electricity storage options meant that the complete potential of an on-site solar plant could not be realized.WRII has found that net-metering regulations for rooftop solar projects in Karnataka, introduced in November 2014, were met with moderate success among C & I consumers. The adoption among residential consumers was slow due to information gaps about financial parameters, net-metering procedures and credible installers.On May 2, 2016 gross metering scheme is introduced for both categories of consumers. WRII intends to look into the effectiveness of the new scheme.Off-site solar procurementGrid-connected solar power projects in Karnataka, commissioned before 31 March 2018, were exempted from payment of wheeling, banking charges and cross subsidy surcharge for the first 10 years for sale to 3rd party customers.Since the typical payback period for a utility scale solar project is around 7 years, this order provided long term clarity for investors, solar project developers and consumers. For certain categories of consumers (commercial), the exemption meant that solar energy became more viable. However, challenges in procuring land and bottlenecks in power evacuation, may delay the large scale deployment of solar projects to the latter half of 2016.
Unlocking urbanization —– leveraging coalitions for transformative change in Indian cities
Authors: Dhindaw Jaya , Ganesan Kanchana , Pai Madhav
Published: May 2017

India is going through the early phase of urbanization with 33% of its citizens currently living in urban areas, with the number expected to go up to 40% by 2030. The sudden growth in Indian cities has led to challenges in infrastructure provisioning and service delivery which have not kept pace. Evidence in the form of case examples from across cities point to the possibility that there is room for leveraging disruptive innovation in filling the space in efficient service delivery via institutions outside the formal public setup. In the context of the gaps in governance, this paper seeks to examine the role of institutions and the potential of coalitions as ‘agents of change’ that can empower and equip the government and citizenry with technical capacity and methodologies for action, enabling sustainable development and eventually, triggering broader cross-sectoral, city-wide transformation.
Al hilo de las lecturas escolares y las nuevas demandas educativas
Authors: Martos García Aitana
Published: May 2017

El artículo revisa desde un punto de vista crítico el estado del arte sobre las lecturas escolares, desde sus supuestos teóricos a su instrumentación didáctica y los puntos de vista de los profesores. A este respecto, son revisadas las aproximaciones de distintos paradigmas y autores, cuyas referencias y aportaciones son contrastadas con la encrucijada cultural actual y las percepciones de los alumnos y los docentes. La lectura y la escritura clásicas son desbordadas por conceptos como multialfabetización, transmedia, fan fiction, etc., y es la escuela la que debe facilitar modelos integradores y eclécticos de lecturas. También debe hacer converger los distintos medios y fomentar la participación (Jenkins), y todo ello sin perder como horizonte la literacidad crítica.
Development of a structural and algorithmic model of pur-poseful actions of experts in maintenance and repair
Authors: Koptev A. N. , Popovich A. A.
Published: May 2017

The paper deals with the statement and ways of solving the problem of modeling the activity of an expert in maintenance and repair using the principles of structural and algorithmic as well as other ways of describing the activity.
The influence of high-frequency current heating temperature on the structure and properties of VT9 alloy blanks for high-speed stamping
Authors: Kostyshev V. A. , Pityugov M. S.
Published: May 2017

The paper is devoted to the influence of technological parameters and methods of high-frequency current heating on the structure of VT9 alloy blanks for high-speed stamping. The influence of the blank structure on the strain stress state, the complex of mechanical properties, the energy of deformation and stability of stamping equipment are analyzed. Comparative estimation of high-frequency current heating and oven heating is given. The procedure of carrying out the experiments is presented and the analysis of their results is given.
Verifying models of mechatronic systems «man-centrifuge» for ground and space usage on the basis of set theory
Authors: Anshakov G. P. , Akulov V. A. , Balakin V. L.
Published: May 2017

The paper presents the results of verification of the proposed criterion for assessing the adequacy of artificial gravitation and Earth gravitation. The validity of using this criterion in solving the similarity / dissimilarity problems of artificial gravitation and Earth gravitation is shown.
Means of illumination of an underwater situation of manned submersibles
Authors: Alekseev A. V. , Belenky V. N. , Olenin A. L. , Smirnov G. V.
Published: May 2017

The possibility of creating a complex system of illumination of an underwater situation of a manned submersible is discussed in the paper. A technology of carrying out underwater technical operations is proposed which will make it possible to reduce the time of searching the object of research, to order the process of search and to guarantee the positive result that will facilitate the operators work and improve the safety of operations.
Models of financial interaction between investors in project financing
Authors: Bogatyryov V. D. , Gorbunov D. V.
Published: May 2017

The paper presents a complex of interconnected economic mathematical models describing material and financial flows during the collaboration of investors and the bank in project financing. The models take into account a number of common parameters, which makes it possible, with their joint usage, to implement coordinated collaboration in a one-level system.
Approaches to the evaluation of fuels for hypersonic engines
Authors: Sergeev S. M. , Petrukhin N. V.
Published: May 2017

The article presents gas flow parameters in four cross- sections of the engine at the flight speed of 8M at the altitude of 20 km for various hydrocarbon fuels. The data were obtained with the use of a multi-purpose program complex. The analysis of the obtained results allowed determining the level of requirements for the basic properties of fuels for hyper-sonic ramjet engines and arguments in favour of developing a new fuel for hypersonic ram-flow jet engines as well as new methods for its evaluation.
Thermal state of combustor can elements
Authors: Grechishnikov O. V. , Ostapets I. I. , Roslyakov A. D. , Tsybizov Yu. I.
Published: May 2017

Materials for providing the thermal state of the elements of a two-staged gas turbine combustion chamber for terrestrial applications are presented. The factors that affect the temperature of combustor can rings are analyzed. A significant influence of flow characteristics and range of burners in the main loop on the combustor can wall temperature is shown and it is also shown that the task of ensuring acceptable combustor can wall temperature in accordance with the TOR is reduced, first of all, to the task of providing an optimum structure of the flow of fluid in the inner cavity of the combustor can.
Optimal distribution of turboprop engine free energy between the screw and the jet with mass characteristics taken into account
Authors: Grigoriev V. A. , Prokaev A. S.
Published: May 2017

The paper presents an analysis of research in optimal distribution of the airscrew thrust and the jet thrust of the turboprop engine. A conclusion is made as to the necessity of evaluating the efficiency of the power plant being a part of the aircraft.
Results of primary operation of NK-37 engine low emission combustion system
Authors: Bantikov D. Yu. , Yeliseev Yu. S. , Lavrov V. N. , Pchelyakov A. A. , Fedorchenko D. G. , Tsybizov Yu. I.
Published: May 2017

The article deals with the results of primary operation of the NK-37 engine low emission combustion system. "KUZNETSOV" company has developed a low emission combustion system, including a double-circuit fuel burner, a traditional type annular combustion chamber and a multistage automatic fuel feeding system, according to the mode of engine operation and ambient conditions. The results of a long- period primary operation of the combustion system incorporated in the NK-37 engine are given in the article.
The usage of high power supply capacity transport spacecraft
Authors: Ivanovich S. N.
Published: May 2017

The paper deals with the problems of using transport spacecraft based on a nuclear power supply system and electric rocket engines for the transportation of payload to the near-earth orbits and exploring the Solar system in the nearest perspective. A method of calculating the parameters of a transport spacecraft power supply complex is presented. The problems of using this type of transport spacecraft at the current stage of space engineering are identified.
Environment of computer-aided analysis of measurement data obtained from space carrier rockets
Authors: Kapitonov V. A. , Kononenko A. V. , Tikhomirov S. A.
Published: May 2017

The paper deals with the environment of computer-aided analysis of measurement data obtained from space rockets. This environment is designed for analysis experts as analysis tools for measuring the data obtained during tests of space rocket equipment.
System of satellite navigation of «Bion-M» space vehicle
Authors: Manturov A. I. , Rublyov V. I. , Muntyan R. Yu.
Published: May 2017

The paper describes the make up, characteristics and the results of assessing the accuracy of «Bion-M» spacecraft satellite navigation system by the navigation data obtained from the space vehicle.
Experience of implementing «Galaktika ERP» system
Authors: Mkrtychyan A. R. , Karmadonov D. I. , Petrenko E. A.
Published: May 2017

The paper is devoted to problems and ways of solving them by implementing the module of a production planning system «Galaktika ERP». Methods of planning and the report forms on the results of planning are presented.
Self-consistent theory of antennas based on integral equations
Authors: Neganov V. A. , Tabakov D. P.
Published: May 2017

The paper outlines the foundations of a self-consistent theory of antennas. It is shown that the incorrectness of the physical model of the antenna leads to the incorrectness of its mathematical model. Integral representations of the electromagnetic field that become a system of integral equations in relation to the unknown surface current distributions on the emitting area under boundary conditions are proposed as the main instrument of self-consistent analysis. The results of self-consistent electrodynamic analysis for certain types of antennas are presented.
Assessing the strain-stress state parameters of cutting tools and parts during machining
Authors: Stepanov A. A. , Haimovich A. I.
Published: May 2017

The paper presents a method of choosing rational broaching conditions, the optimal geometry of the broach cutting tooth, assessing the strength parameters of broaches and parts using experiment planning and finite-element modeling. Mathematical models for accelerated calculation of geometrical, technological and strength parameters of broaches and parts and for the prediction of the values of these parameters under changed machining conditions are presented. The application of the technique makes it possible to increase the machining accuracy by using the models in calculations of metal cutting on multipurpose computer controlled machines.
Analysis of the influence of low-orbit nanosatellite uncontrolled motion on the possibility of solving navigation and communication problems after its separation from the «Soyuz» carrier rocket upper-stage
Authors: Belokonov I. V. , Kramlikh A. V. , Timbai I. A.
Published: May 2017

The paper analyses a nanosatellites uncontrolled motion relative to its mass center after separation from the upper stage of Soyuz carrier rocket. Stochastic models of the initial conditions of the nanosatelite attitude motion are formulated. The possibility of successful solutions of navigation and communication problems using satellite navigation systems and low-altitude communications networks for LEO nanosatellites is shown.
Calculation of hydrodynamic noise in the diffuser of a pulsation damper flow channel
Authors: Makaryants G. M. , Gafurov S. A. , Zubrilin I. A. , Kryuchkov A. N. , Shakhmatov Ye. V. , Berestovitsky E. G. , Gladilin Yu. A.
Published: May 2017

This article deals with the problem of hydrodynamic noise inside a fluid pressure vibration absorber. The calculation of hydrodynamic noise is based on the results of numerical simulation of fluid flow in the central duct of the vibration absorber. A complete system of hydrodynamics equations is solved with the help of a large eddy simulation turbulence model (LES).
Study of thermal stability of microdisperse filler reinforced composites
Authors: Shustov I. I. , Koytov S. A. , Melnikov V. N.
Published: May 2017

The article presents the results of studies of composite epoxy-filled materials reinforced with different fillers and aluminum-boric-silica microspheres carried out in a thermal gravimetric analyzer.
Method of reducing design aerodynamic characteristics to the results of drain tests of a transport category aircraft model
Authors: Bondar Yu. I.
Published: May 2017

A method of reducing design aerodynamic characteristics to the results of drain tests by adjusting a mathematical model of the aircraft being designed on the basis of an aerodynamic prototype is presented in the paper.
Error distributions in aircraft position determination
Authors: Rubtsov E. A.
Published: May 2017

The paper deals with the problems of determining aircraft coordinates. The widely used Gaussian distribution does not make it possible to analyze extremely rare events with certainty. The ICAO- recommended double-exponent distribution does not meet the requirements of accuracy either. It is, therefore, necessary to look for new distributions. The paper gives examples of such distributions as well as examples of solving problems of detecting violations of separation.
Influence of subwave details of microrelief on the diffraction pattern of gaussian beams
Authors: Savelyev D. A. , Khonina S. N.
Published: May 2017

The paper deals with the influence of subwavelength details with two types of etching of microrelief (ridge and groove) on the diffraction pattern. Modeling the diffraction of uniform-polarization radiation corresponding to both a Gaussian beam and a vortical Gaussian-Laguerre beam is performed by the method of solving Maxwell equations by finite differences in time domain (FDTD). The characteristics and features of the diffraction pattern in the near zone, including those connected with the formation of the longitudinal component of the electric field are determined.
Diagnostics of computer modules of the Superjet-100 aircraft using the method of boundary scan
Authors: Grechishnyikov V. M. , Kuritsky A. A. , Manuilov I. Yu.
Published: May 2017

The article deals with the questions of search, localization and identification of manufacturing defects in printed boards of digital modules of the aircraft Superjet-100 avionics using the method of boundary scan.
Constructive actions for decreasing the acoustic pressure inside space-rocket products
Authors: Popov P. A. , Sindyukov A. A.
Published: May 2017

Possible measures for decreasing the whisper of pressure inside the reentry vehicle and intertank bay are outlined in the paper; a formula for calculating the total decrease of acoustic loading through the use of different measures is given.
Method of calculating vibrations in a pipeline with damping supports made of MR material
Authors: Bezborodov S. A. , Ulanov A. M.
Published: May 2017

A method of calculating vibrations in a pipeline of an arbitrary shape with damping supports made of MR material with the help of the finite element method ANSYS software is developed. The method takes into account the non-linearity of MR material, it makes it possible to determine the amplitudes of pipeline vibration and the stress in the pipeline. The calculation results are confirmed by an experiment with the ARAMIS measurement system. The method can be used for placement of pipelines.
Elimination of gas dynamic resonance modes of vibration loads of gas distribution station pipeline fitting
Authors: Shabanov K. U. , Kryuchkov A. N. , Ermilov M. A. , Balyaba M. V.
Published: May 2017

The article contains a study of the modes of resonance interaction of a high-speed gas flow exiting from the metering sections of pressure regulators with their elements. It is shown that the interaction leads to a significant increase of the valve noise due to the tone component of the spectrum of vibration energy which occurs at the frequency characteristics of pressure fluctuations in the pipeline, the vibration of the controller output flange, as well as the external valve noise. The results of analyzing the prerequisites for resonant interaction of the gas flow with the regulator structural elements including the pylons of the central fairing are presented in the paper. It is shown that an increase in the output flow rate above a certain value (about 40 m / s) gives rise to discrete components of the spectrum of pressure fluctuations. The results of experimental analysis of the pressure regulator elements showing practical coincidence of the frequencies of discrete components of the flow pulsation spectrum and free oscillations of construction elements are also presented. Modal analysis of the natural oscillations of regulator elements is performed by tapping. Measures to remove resonant interaction of the output flow with the pylons that consist in installing special flow-splitting structures - perforated cylindrical sleeves are proposed. Other measures to eliminate the resonant interaction under consideration are also possible.
Stimulation electromyography in determining the mechanism of therapeutic action of adaptive feedback for patients with traumatic disease of the spinal cord
Authors: Bogdanova L. P.
Published: May 2017

The aim of this work was to study the mechanism of the therapeutic action of the adaptive biofeedback method using visual and auditory feedback to repair movement disorder in patients with traumatic disease of the spinal cord in case of complex spine fracture on the basis of data on the changes in electrophysiological properties of muscles and spinal motor neurons involved in the pathological process. Sixty four patients were treated and tested in the first month after injury, 40 of them male and 24 female. The age of the patients ranged from 19 to 40 years, the average age being 28,3 years. All the patients were subjected to a complete orthopedic and traumatological, neurological, laboratory, radiographic and electrocardiographic examination. Electroencephalography was also carried out if required on therapeutic grounds. After adaptive biofeedback an increase in total excitability of the patients spinal motor neurons by a factor of 2,2 was noted. The involvement of alpha-BMN increased by a factor of 2,5 and that of alpha TNM increased by a factor of 1.6 approaching the performance of healthy people. The sensitivity of primary muscle endings increased by 64,5%. The degree of attenuation of the re-induced spinal reflex practically did not change.
Choice of design characteristics of «garbage collector» spacecraft with a low-thrust electrojet engine
Authors: Ishkov S. A. , Filippov G. A.
Published: May 2017

The paper is devoted to the problem of debris in the near-Earth space. We investigate a method of cleaning the space of large fragments of space debris using a garbage collector spacecraft with a low- thrust electrojet engine. A mass model of one-shot and shuttle spacecraft has been constructed. A mission trajectory plan is presented that includes the spacecraft flight from the parking orbit to that of debris location, its descent to the surface of the Earth and the return of reusable spacecraft to the parking orbit. Analytical relationships for the calculation of the spacecraft design parameters have been obtained for the proposed criterion for evaluating the effectiveness of the logistic space mission and the assumption about constant thrust acceleration. The results of calculation of the design parameters are summarized.
“Squirrel cage” flexibility in supports of aviation gas turbine engine rotors
Authors: Degtiarev S. A. , Leontiev M. K. , Popov V. V.
Published: May 2017

Elastic damper supports composed of elastic elements of the squirrel cage type are widely applicable in the design of aviation gas turbine engines. They are used for engine frequency detuning from unwanted resonance frequencies and for unloading of hydrodynamic dampers from the rotor weight. Squirrel cage elements are designed in different ways but the schemes with straight, compound and curvilinear rods are the most frequently used ones. Total flexibility of the rods that form the squirrel cage mainly determines the flexibility of the whole elastic-damper support in general. References [1] and [2] give simple equations to obtain radial stiffness coefficient of the elastic part of the squirrel cage with straight rods of the rectangular cross-section. However, the squirrel cage transmits not only radial forces but axial ones and moments as well. This fact necessitates consideration of other coefficients of the general flexibility matrix of the squirrel cage. The present article presents a methodology of determining the flexibility matrix of an elastic bush of the squirrel cage. The given methodology is applicable for bushes with straight rods (finite-element methods should be used for compound and curvilinear rods). Flexibility matrix components are obtained using the methods of strength of materials. The elastic bush of the squirrel cage is considered as a set of straight short rods restricted by stiff flanges from the butts. As a result, an analytical equation depending on the bush characteristics was obtained for every matrix component. As a test example, a flexibility matrix for the defined characteristics was obtained. Meanwhile, the time of obtaining the flexibility matrix does not exceed fractions of a second. Similarly, a flexibility matrix was obtained using calculations in the finite-element complex. The difference between the results obtained was less than 1%. The given algorithm and the flexibility matrix obtained with its help may be used for the simulation of support units of aviation gas turbine engines in rotor dynamics tasks.
Check and prediction of gas-turbine engine’s technical state
Authors: Zotin N. A.
Published: May 2017

The problem of check and prediction of a gas-turbine engines technical state is presented in verbal and mathematical statements in the paper. The mathematical statement of the problem is presented as a ternary system. This system consists of three components: initial data for solving the problem; a set of conditions and restrictions to be accomplished in the process of solving the problem; the required result to be obtained by solving the problem. The initial data for solving the problem consist of a set of propulsion unit parameters and environment parameters registered at different time moments as well as sets of expert reports on the technical state of gas-turbine engines. Among the limitations imposed when solving the problem we can name a fixed list of the registered parameters of the power plant as well as the absence of the possibility of purposefully extending the base of empirical data. The required result to be obtained by solving the problem includes: a model for determining check, diagnostic and prognostic parameters; the function of calculating the criteria of the technical state; the function of extrapolating the above-mentioned criteria; a set of control, diagnostic and prognostic criteria. Each component is described in the paper using the semantics of sets and multisets.
50 n thrust correction engine for the "Luna-resurs" lunar module descent engine
Authors: Ageenko Y. I. , Pegin I. V. , Chesnokov D. V.
Published: May 2017

Research to develop a 50 N thrust correction low-thrust liquid rocket engine with a deflector-centrifugalscheme of mixing nitrogen tetroxide and unsymmetrical dimethylhydrazine propellants on the inner wall of thecombustion chamber has been conducted at the Chemical Machinery Design Bureau named after A.M. Isaev. Inthe deflector-centrifugal mixing scheme developed at the Chemical Machinery Design Bureau the oxidizer getsto the conical deflector via the jet nozzle and is transformed into a primary film running off the edge of thedeflector onto the inner wall of the combustion chamber where it is transformed into a secondary film that flowsalong the wall of the chamber to the point of meeting the film from the centrifugal fuel spray nozzle coaxial withthe combustion chamber. Upon meeting the films of oxidizer and fuel continue flowing along the wall of thecombustion chamber at the same time penetrating each other and carrying out the liquid-phase mixing with theformation of transformation products of hypergolic fuel. Thus, practically all the fuel gets to the inner wall of thecombustion chamber, participating in its cooling and removal of a considerable part of the heat flow directedalong the wall of the combustion chamber from its critical section in the direction of the nozzle head. The enginehas the highest (in its class) geometric nozzle expansion ratio ( Fа =200) among analogues of domesticproduction, meanwhile preserving acceptable dimensions and weight characteristics. The combustion chamber inthe engine designed is made of a niobium alloy with a protective heat resistant coating - molybdenum disilicideMoSi2 deposited on the inner surface while niobium disilicide NbSi2 formed by silicon impregnation of aniobium alloy is used on the outer surface. During the firing tests the jet centrifugal scheme of organizing thework process in the combustion chamber designed at the Chemical Machinery Design Bureau confirmed itsefficiency in a 50 N-thrust engine. The adopted design and technological solutions in creating a 50N thrustengine ensured high power and energy-mass characteristics, as well as stable engine performance in a wide rangeof pressures of fuel entering the engine: up to 70.3 N in power augmentation and up to 45.9 N in throttling
Assessing reduction gear mass in the problem of optimizing parameters of the working process of a turboprop engine at the initial design stage
Authors: Grigoryev V. A. , Zagrebelnyi A. O. , Prokaev A. S. , Kuznetsov S. P.
Published: May 2017

The paper analyzes mathematical models of the mass of the reduction gear as part of a turboprop enginepower plant in the problem of optimizing the parameters of the working process of the gas turbine engine at theinitial design stage. The necessity of optimal matching of the main parameters of the power plant and the aircraftbased on their system performance criteria is the main feature of the initial design of turboprop engines. To solvethe problem of optimizing the parameters of the engine work process, under certain design constraints, it is importantto know the take-off weight of the aircraft in the formation of which the weight of the power plant with aturboprop engine is one of important components that actually determine the coordination of the aircraft andengine parameters. The mass of the reduction gear of a turboprop engine makes up a significant part of the powerplant mass. The existing models of the mass of the power plant with a turboprop engine do not separate theweight of the gear from the weight of the power plant. Thereby, the reduction gear weight is erroneously associatedwith gear parameters used in the model of the mass of the engine. This does not include theobvious dependence of the gear mass on the transmitted power which is closely linked to the distribution of the free energy of the turboprop engine.
Development of methods of designing modern gas turbines
Authors: Inozemtsev A. A. , Khairulin V. T. , Tikhonov A. S. , Samokhvalov N. Yu.
Published: May 2017

The paper is focused on the evaluation of integral and local parameters of advanced aero engine highpressureand low-pressure turbines using the method of 3D numeric simulation in ANSYS CFX. The modelsused were very detailed high-pressure and low-pressure turbine models with adjoined cavities and a transitionduct consisting of 577 million finite elements. Numerical analysis was conducted both in stationary and nonstationarysetup using BSL and SST models of turbulence. The resulted design data were verified against theturbine test results. Deviations between design and test data, both local and integral, are insignificant (local deviationis not more than 5%). The results of numerical analysis show high level of turbines efficiency. The currentconfiguration was optimized based on the results of verification, which allowed increasing HPT design efficiencyby 0.4%. The model was taken as a basis for a series of works aimed at improving the key parameters of bothindividual turbine components and the module on the whole.
Validation of CFD-models of gas turbine engine uncooled turbines
Authors: Matveev V. N. , Popov G. M. , Goryachkin E. S. , Smirnova Yu. D.
Published: May 2017

In the course of the work presented in the paper the agreement between the parameters obtained bymethods of computational fluid dynamics and the values used in the JSC "Kuznetsov" in the mathematical modelof a gas-turbine unit NK-36ST was verified. A lowpressure turbine and a free turbine of a stationary gas turbineplant were the object of research. During the research three computational models of turbines with differentnumbers of finite-element computational grids were devised that do not take into account the presence of theturbine cavities. The models of the first level contained approximately 450,000 items in one blade row, the modelsof the second level - approximately one million elements in one blade row, while those of the third level -about 2 000 000 items per one blade row. A model that includes turbine cavities was also constructed. Diagramsof pressure profiles, total temperature, flow angle and turbulent viscosity throughout the height of the flow sectionderived from the preliminary CFD calculations were set as boundary conditions at the inlet of the turbines.The calculation was performed in the Numeca Fine/Turbo software package and resulted in obtaining the basicparameters of the flow in turbines. The dependences of the flow capacity of the turbine А, turbine efficiency,turbine pressure ratio, the outlet flow angle in absolute frame on the parameter n/C*эфwere found ontheir basis.The influence of the calculated mesh dimensions on the results of turbine characteristics simulation wasinvestigated. The effect of taking into account the turbine cavities on the design characteristics of the turbine inthe process of simulation was also investigated. Recommendations for constructing computational models ofuncooled axial turbines of gas turbine engines are developed, the possibility of optimization and preliminarycalculations using models that do not take into account the turbine cavities is justified.
Peculiarities of modeling the work process in a low-pressure compressor of a gas turbine plant
Authors: Matveev V. N. , Popov G. M. , Goryachkin E. S. , Smirnova Yu. D.
Published: May 2017

The problem of weight decrease is crucial for modern gas turbine engines. Application of supersonicand transonic compressors is one of the ways of solving this problem. This allows reaching a higher pressureratio at each stage than while using subsonic compressors and thus reducing the number of stages required toproduce the desired value of pressure ratio. In compressors of this kind the flow is slowed down due to a systemof shockwaves in the supersonic part and due to the flow deflection in the diffuser channels formed by the rotorblades and guide vanes in the subsonic part. The design of new compressors and modernization of old ones isinextricably connected with the usage of computational fluid dynamics methods at the present stage of engineconstruction development. The necessity of simulating a shockwave system imposes high demands on the constructionof a computational mesh. In particular, the choice of the method of parameter passing between the domainsof rotating blades and those of fixed guide vanes is an urgent task. It is shown in the paper that the use ofdifferent methods of averaging and parameter passing between domains can make a significant difference incompressor design characteristics (for example, a three-stage low-pressure compressor). Three methods of passingparameters between the domains that are used in the software package NUMECA/Fine Turbo are analyzed.The calculated compressor characteristics are compared with the experimental data at different rotation frequenciesof the rotor. The data obtained show the adequacy of the numerical model of the work process in the compressorunder investigation. Typically, air bleeding for various needs takes place in compressors. Compressorperformance changes when the air enters it, which should be considered in the calculations. It is shown in theexample of the compressor tested that the inclusion of air bleeding results in quantitative and qualitative changesin the compressor performance. Among other things, parameters like pressure ratio and dynamic stability marginare changed, which may lead to inconsistent operation of the compressor as part of the engine. Thus, a conclusionabout the necessity of taking into account the simulation of air bleeding in the calculation of supersoniccompressors is made. The results obtained make it possible to expand the understanding of the working processof supersonic and transonic compressors and can be used later in the creation of numerical computational modelsof compressors of this type.
Research of shaft seals made of porous wire «metal rubber» material
Authors: Zhizhkin A. M. , Zrelov V. A. , Zrelov V. V. , Ardakov A. Yu. , Osipov A. A.
Published: May 2017

The possibility of using elastic porous elements made of "metallic rubber" (MR) as rotor seals is discussedin the paper. The technology of manufacturing of such elements is developed for the mechanical dampingof vibration in mechanical systems where they are widely used. Comparative analysis of rating curves of labyrinth,honeycomb, brush seals and seals made of MR material has shown that seals made of MR material havebetter rating curves than labyrinth and honeycomb seals, but slightly worse ones than those of the brush design.Therefore, the use of porous MR material shows promise for making parts of the seals for gas or oil cavities ofrotors. Seals made of MR material are designed for optimum performance in the most demanding aerospace sealingapplications where high speed and vibration are the norm, and where axial shaft movement takes place. Aninstallation imitating conditions of using rotor seals is designed for the purpose of analyzing seals made with theuse of MR material.
Life cycle assessment of the production chain of oil-rich biomass to generate BtL aviation fuel derived from micraoalgae
Authors: Gehrer M. , Seyfried H. , Staudacher S.
Published: May 2017

Considerable efforts are made to generate drop-in aviation fuels from microalgae to avoid competitionwith food production. Synthetic biofuel from oil-rich biomass is produced along four process lines: cultivation,harvest, extraction of raw material and conversion to fuel. This study deals with the life cycle assessment of fuelobtained from cultivation of the fresh water alga Auxenochlorella protothecoides and concentrates on the cultivationin open ponds as well as the harvesting steps preconcentration, electroporation and dewatering. Energybalance and environmental impact is analysed using GaBi software and data base. The main goal is to identifythose factors or processes exerting the strongest impact, either environmentally or from the point of view of theenergy balance. Production of one kilogram of dry oil-rich algal biomass (kg DM) consumes 118.56 MJ of primaryenergy. The primary energy demand is apportioned as follows: 71.7 % during proliferation in Erlenmeyerflags and bubble columns, 15.5 % by cultivation in raceway ponds and 12.8 % in preconcentration, electroporationand dewatering. This converts into a net energy ratio (NER) of 0.266 and a CO2-equivalent of 6.45 kg CO2per kg DM. These values are disadvantageous when compared to kerosene (NER=0.867, 0.384 kg CO2 per kgkerosene). Production can be optimized using process energy from regenerative sources such as hydroelectricpower (NER = 0.545, 1.27 CO2 per kg DM). In this case total primary energy input must be corrected for theportion of renewable sources resulting in a NERcorr of 3.04. CO2-equivalents per kg DM remain unfavourablyhigh as compared to kerosene; the main driver responsible for this discrepancy is the usage of freshwater andfertilizer.
Dynamic elastic and damping models development and research for technical objects vibration safety providing
Authors: Shakirov F. M.
Published: May 2017

This article considers single-mass elastic-damper model of oscillating system; simplified classic versionswith pendants in the form of rheological models of Poynting-Thomson, Kelvin, Maxwell, Hooke can be derivedfrom this model. The difference between this model and other classic versions is that the components of researchedmodel suspension system are based on different foundations; one of foundations can be vibro-active.Model has two modifications, the difference between these modifications is that in one case elastic part of suspensionsystem is based on vibro potentially active foundation and in other case elastic damper part of suspensionsystem is based on vibro potentially active foundation. The article also contains mathematical models ofthese modifications with allowance for damping of nonlinear type. Dynamical functions of variation are researched.In this variation vibrations can be transmitted from foundation to protected mass through elastic component.Article shows the cases of force and kinematic vibro-loading of mass with appliance of frequency functionson absolute and relative parameters. Dynamics of researched model is identical to dynamics of classicmodel in case of force vibro-loading of researched model. New properties (two invariant points) appear on amplitudefrequency characteristic of relative parameter in case of kinematic vibro-loading. This fact is used foroptimization of damping level in order to minimize the resonance amplitude. The range of low-frequency vibrationisolation is not less than the range of conservative oscillating system. Its size depends on damping and stiffnessof elastic elements, so the choice of these values is associated with the achievement of compromise betweenlimitation of the range of resonance oscillations and providing of the low-frequency vibration isolation of therequired quality.
Analysis of the thermal state of aircraft engine supports
Authors: Vinogradov A. S. , Badykov R. R. , Fedorchenko D. G.
Published: May 2017

The paper discusses the main sources of heat that enters the aircraft engine support. It explores the waysof determining them and provides their quantitative comparison for certain operating conditions of the compressorsupport. On the basis of determining the amount of heat coming from each of the sources and the results ofthe previously performed thermogasdynamic design hydraulic analysis of the engine support air cooling is carriedout and the distribution of convection coefficients and temperature on the walls of the support is calculated.Then the structural heat calculation is performed. On the basis of the structural analysis the temperature distributionin the support elements is determined. Examples of estimating the impact of the amount of heat from differentsources as well as the impact of changing the amount of heat from an individual source on the level of oilcirculation in the engine are given. The rates of heat transfer for various sources depending on the engine operatingcondition are compared. On the basis of the proposed sequence of calculations a methodology of determiningthe thermal state of aircraft engine supports was compiled that will make it possible to choose the required coolingsystem and adjust the basic parameters of the engine oil system.
Calculation method for determining the characteristics of elastic-damping suspension made of metal analoque of rubber for plain bearings
Authors: Parovay Ye. F. , Parovay F. V.
Published: May 2017

The paper is devoted to creating a comprehensive methodology for calculating the characteristics of hydrodynamicbearings of a new type. The design of these bearings has several advantages in comparison with rollingbearings and traditional hydrodynamic bearings. However, the creation of effective bearings requires the developmentof their design methodology based on accurate mathematical apparatus and the use of the capabilities ofmodern CAE-programs. One of the most important stages of the design is to determine the required parametersof the elastic suspension material. The paper discusses developed mathematical models of the "working gap -bearing - elastic suspension" system behavior. The model is created with the aim of determining the characteristicsof the elastic suspension material to ensure the best operation of the bearing. The mathematical apparatusdeveloped is based on the model of V.N. Buzitskiy and A.A. Troynikov for the MR material and takes into accountthe peculiarities of the lubrication flow in the gap of the bearing. The paper presents a method of calculatingthe basic characteristics of the MR material, such as wire diameter, deformation and material density. Therequired parameters are determined on the basis of the results of CFD calculations of lubricant flow characteristics(pressure distribution in the working gap, the amount of deformation etc.)
Method of gas turbine malfunction diagnostics using hybrid intellectual systems
Authors: Antropov P. G. , Dolinina O. N. , Shvarts A. Y.
Published: May 2017

Methods of improving the safety and efficiency of gas turbines are analyzed. The existing diagnosticmethodologies and software for compression stations are reviewed. Lists of significant diagnostics parameters,typical faults and their causes are compiled. A model of a hybrid intellectual system of gas turbine fault diagnosisbased on artificial neural network and fuzzy inference is introduced. The fuzzy inference method which allowsprocessing an arbitrary number of intermediate variables and transitive relations is described. Moreover, themethod makes it possible to take into account the inaccuracies in expert knowledge not only in describing thefacts of an application domain but also in cause-and-effect relations between them. The implementation of theproposed model and the method in the system of taking decisions that makes it possible to reveal both the presenceand character of the faults and their possible causes is described. The proposed system makes it possible toimprove the accuracy and completeness of gas turbine diagnostics, which, in its turn, will increase the labor safetyfor the compression station staff as well as the promptness of repair and maintenance. Thus, the application ofthe system may have a positive effect on the service life and economic feasibility of gas turbines.
Conception of cycle life additivity and its application for determining the resource of aero engine disks
Authors: Tumanov N. V. , Lavrentyeva M. A.
Published: May 2017

Taking into account the universal character and high energy intensity of the mechanism of low cycle fatigue(LCF) crack stable growth which ensures a long safety period for the growth of such cracks a conception of cyclelife additivity is proposed. According to the conception the cycle life of an aero engine disk is determined up to thelimiting state connected with the transition of a LCF crack to unstable growth in the critical area of a disk. The cyclelife prior to the first overhaul is calculated by adding the life cycle before the crack origination and that of stablecrack growth (survivability resource); the overhaul period is determined by the survivability resource. The latter isalso the lower bound of the disk life at the design stage. To estimate the overhaul period we suggest using survivabilitydiagrams representing the dependence of LCF crack stable growth in the critical area of the disk on the size ofthe crack. Methods of constructing survivability diagrams have been developed for simple and complex loadingcycles. Examples of applying the conception for the estimation of cycle life of aero engine disks made of wroughtand powder alloys are presented.
Experimental research of heat exchange in a plane channel using the regular thermal regime mrthod with different Biot numbers
Authors: Kolesova E. G. , Veretennikov S. V. , Zhornik M. N.
Published: May 2017

The results of the experimental study of heat exchange in flat channel, executed by method lazerstereolithography, is presented. The studied heatexchange surface represents the thin metal plate forming one ofchannel sidewalls. Researches were performed under different criterion Bi in broad range criterion Re.For determination of heat-transfer coefficient is used infrared heat diagnostics, in base which prescribed methodof the regular heat mode of the first sort. At first the metal plate was heated, after through an internal channelturned on blowing cold air. Temperature of plate was measured by infrared thermography. In processing theresults were based on graphics logarithm excess temperature from time. Slope ratio of the curves is the rate ofcooling of the plate. The borders of application of this method are experimentally determined from criterion Bi.The experimental results coincide well with the known criterion dependence Nu=0,018Re0,8. Developedexperimental setup and methodology of transitional experiment allow to determine the heat transfer coefficientin forced for restricted flow, when the regular warm mode of 1 type is realized.
Combined treatment technology for slot channels of cooling systems
Authors: Rodionov A. O. , Suhochev G. A. , Kodentsev S. N. , Smolyannikova E. G.
Published: May 2017

The article presents the results of the searching and experimental research in the field of treatment of discontinuoussurfaces in parts of cooling systems. The existing methods and means of technological equipment forproviding of quality surface treatment of slot channels are described. Slot channels are especially technologicallycomplex for treatment. A new method of combined treatment was proposed based on an analysis of existingtreatment methods. The method allows to achieve the specified operational characteristics of .slot channels.Basic technological principles to design a new method of finishing of small-flow parts, which combines finishingand control operations, are developed. In article the mechanism of combined finishing for slotted channelsare described. The results of experimental verification of the technological capabilities of the combined treatmentare presented.