2012. № 58
Methods and tutorials | |
In article the original technigue of teaching of discipline “Ecology” to student ENGECIN MAI is submitted. Convincing results of the analysis of statistic of progress of student and eхternal interactive testing interactive technologies of student in half-year after studying a rate “Ecology” a resulted at carrying of federal eхamination in sphere of the higher professional education (FEPE) organized by the Ministry of education and a science of the Russion Federation. Keywords: interactive technologies, internet testing in a mode on line, a mobile teaching material, residual knowledge, ecological management. |
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Mathematics. Physics. Mechanics | |
This paper suggests a more generic mathematical model of vehicle with omnidirectional wheels, which describes not only the plane motion when the platform and all wheels are considered as a rigid body, but also the platform’s spatial motion. Only using this motion allows us to analysis the characteristics of the equipped on platform inertial measurement unit (IMU) in purpose to create a criterion for choosing parameters of embedded sensors according to the precision of control algorithm. We also create a program, using some control rules, including PID regulator and optimal control algorithm, for simulating the vehicle motion. Keywords: mathematical model, vehicle with omnidirectional wheels, spatial motion, simulation. |
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Aviation technics and technology | |
The study was perform to examine dynamic response of a ship-based helicopter and its payload during emergency landing to the ship. The helicopter was impact at different forward velocities and different angles of impact with ship’s superstructure (hangar). The cause of the accident is an engine failure. During this study numerical simulations of a helicopter dynamic were executed for different initial conditions. Total acceleration versus time responses of airframe and payload were obtained. Peak acceleration of payload were calculated for each forward velocities and angles of impact. Keywords: ship-based helicopter; payload; emergency landing; finite element method; dynamic response. |
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In this article there are presented the results of research of comparative evaluation of landing safety of AN-124-100 in landing configuration 30/17 и 40/17 for the purpose of approving an acceptable risk level of landing in configuration 40/17 and for approving a practicability of certification of this aircraft for usage in airlines in both of these two configurations. Keywords: flight safety, risk. |
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Numerical investigation result are present to demonstrate an influence of energy supply influence on the shock-wave structure in the entrance device of external compression under given operating mode. It is shown, that energy supply in the filling undisturbed flow can be used for the change of shock-wave structure arising in an input of the entrance device under the given operating mode. Keywords: airplane, entrance device, energy supply, shock-wave structure, Godunov's method |
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This article describes methods for isolating anchor image applied to the problem of localization of unmanned aerial vehicle (UAV) based on passive visual scene. The estimates of the accuracy of determining the position of UAVs, depending on several factors taken and recommendations on the use of the proposed methods and formulated the problem for further research. Keywords: pattern recognition, key features of the image, the localization of the location of UAVs, precision positioning |
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The technique of spin investigation of maneuverable aircraft is described. The technique includes wind-tunnel tests, numeric evaluations using qualitative methods of nonlinear dynamics, mathematical simulation and piloted simulation using fixed-base flight simulator. Recommendations for spin flight tests are formulated. Keywords: spin of maneuverable aircraft; fixed-base flight simulator |
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Results of working out of numerical model and data of a computational estimation of characteristics of random vibration of aeronautical engineering articles in the conditions of joint flight with the carrier are presented. Dependences for spectral characteristics and vibrational acceleration and stress levels in various points of an article’s structure are received and zones of maximum levels of vibration and stresses for the articles placed on an external suspension of the maneuverable carrier are defined. Results of numerical experiments are compared by use of article’s dynamic models with various levels of complexity. Keywords: aircraft carrier, oscillations, finite element method, beam, shell, dynamic state, vibrational acceleration, vibrational stress,stationary vibration, spectral density |
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Space technics and technology | |
The issues of the ground launch complexes’ operations based on advanced orbital constellations’ deployment strategies are discussed. The selection of the launch vehicles supporting the required orbital constellation architecture as well as corresponded ground launch complexes should be performed taking into account limitations of ballistic, technological, environmental and financial nature. The mathematical programming optimization problem is formulated and the solution method is described based on the branch and bounds method. The methodology for the allowable plans’ synthesis is suggested integrating the problem of allocation approach and branch and bounds method concept. This methodology is to be implemented jointly with the known methods of the falling rocket stages’ environment impact evaluation and ground space infrastructure economical optimization allowing management of the ground launch complexes during deployment of the advanced satellite constellations. Keywords: space activities; ground space infrastructure; launch vehicle; launch means; environment situation; spacecraft; orbital constellation; deployment strategy; organizational and technical system control optimization |
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The problem is considered of the zone definition where the launch vehicle’s element should separate to fall into the assigned ground area. The problem is shown to be ill-defined, and a set of the solutions exists. The approach is suggested allowing determining the separation zone securing the separated element falling into the assigned ground area under the atmosphere and wind parameters variation at minimal decrease of the spacecraft injection accuracy. Keywords: launch vehicle; spacecraft; separated elements; new launch pads; perturbing factors; atmosphere parameters; separation zone; dispersion ellipse; falling zone; ignition accuracy |
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The article presents mathematical model for evaluation of availability factor of the served devices at the orbital space station. The model allows for reliability of the said device and time for recovery and scheduled preventive maintenance. The model for specification of distribution function for the period of preventive maintenance under conditions of accidental load of the device is provided. Keywords: orbital stations, reliability, availability factor, recovery, preventive maintenance. |
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The results of numerical calculations of aerodynamic characteristics for two different grid-type surfaces under free molecular flow are presented. The relationships between transmission and exchange factors and mesh density, azimuthal and polar incident angles for particles, and local accommodation coefficients are examined. The domain of applicability for an assumption on mesh azimuthal symmetry is estimated. Keywords: grid-type surfaces, aerodynamic characteristics, pulse exchange factors, transmittance, free molecular flow. |
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The article dwells on the model of reliability of the elements operated at the orbital space stations. The model allows for a possibility of periodic adjustment or preventive maintenance of the element in order to eliminate the effect of degradation of the said element. Mathematical model of reliability of such element is provided, and asymptotic reliability laws of the serviced element are obtained. Keywords: orbital stations; reliability; variable failure rate; preventive maintenance; recovery. |
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The analysis of experimental data to model meteorite impact in order to use them to determine the interaction between particles of artificial cloud formations with cosmic bodies. The result obtained by empirical relationships, which are recommended for use in calculations of asteroid impacts on high-speed particles. Keywords: craters, shock-explosive impact, highspeed impact |
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Aerospace propulsion engineering | |
The numerical simulation method, developed at Keldysh Research Center, is used for the research into special features of the working process in sub-scale combustion chambers of the LRE propelled by oxygen and hydrocarbons (kerosene). The chambers using jet-centrifugal injectors and operating to the gas-liquid scheme are considered. The influence of structural parameters and operating conditions of injectors, and also of the jet interaction on processes of flow, mixing, combustion was studied. Keywords: combustion chamber, liquid rocket engine, numerical simulation. |
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The computing capabilities of modern digital electronic ACS GTE allow to increase essentially quality of control of aviation engines. One of such capabilities relate to application of the high level integrated on-board mathematical model of engine (OMME) in ACS - the full thermogas dynamic mathematical models of engine working in real time. Using such models makes it possible to control the engine parameters, which directly characterize efficiency of using of engine, such as thrust, specific oil consumption, coefficient combustion efficiency , gas dynamics stability margin etc. Besides, it is possible to implement the compensation of sensor failures of controlled and external parameters, Р*1 и Т*1. Using of full thermogas dynamic models of engine as a part of ACS is considered to be one of the perspective direction in the development of aviation GTE in perspective foreign engineering of digital ACS. Keywords: control system, on-board model, unmeasured parameter, sensor fault, validation |
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Preliminary study of impact of heat regeneration and intercooling on turboshaft engine effective efficiency is described. Keywords: effective efficiency; available heat drop; cycle parameters; heat regeneration; intercooling |
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The article describes a mathematical model of the TV3-117VM engine used as a fragment of the mathematical model of MI-8MTV flight simulator. The model is structured according to engine automatic control. A real performance of the engine compressor has been used to compute power and fuel consumption. Keywords: mathematical modeling; helicopter flight simulator; gas-turbine engine performance analysis. |
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Electrotechnology. Electromechanics | |
Problems of power and fuel savings and electric quality increasing in autonomous power supply systems (APSS) for prospective aircrafts with power-consuming mostly or completely electrified equipment (ESS of AD with CEE) are considered. The structure of power-consuming combined direct and alternating current PSS without an interstitial constant frequency of rotation speed drive for an alternating current generator with high degree of the electrical power compatibility (that means the minimal sequential power transformations while delivering power from generator to services) is described. The article can be useful for different transport objects application APSS designers. Keywords: autonomous power supply systems (APSS); prospective aircrafts; fully electrified aircraft (CEA); asynchronous starter-generator; inverter with sinusoidal output voltage; power supply. |
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Technical cybernetics. Information technology. Computer facilities | |
This paper describes a software environment designed to allow a calculation and control the accuracy in modeling the processes of heat treatment of products made of materials with varying thermal characteristics (in terms of eutectoid transformations), based on a new approach to the solution of unsteady heat conduction equations - the method of "geometric integrals." The calculations were made and obtained the distribution of temperature fields in the thermal processing of various pieces of heat-resistant nickel alloys under conditions of blowing an air stream. Keywords: software tools, visualization, simulation techniques, heat treatment, numerical methods, partial differential equations, integral equations, the accuracy of calculations. |
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This article describes features and the structure of an automated computer system developed for solving the aircraft assignment problem. A brief description of the main system components, data base structure, and user graphical interface is given. Some implementation aspects are considered. Keywords: aircraft planning and scheduling, aircraft assignment problem, automated computer system. |
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Radio engineering. Electronics. Telecommunication systems | |
The article contemplates an approach to the association of situation data fed by two information sources. Optimal universal and case decision rules are offered, as well as an applicable polynomial association algorithm. Whilst making decision rules a number of assumptions of the known rules had been omitted. Keywords: association; information sources; target situation; tertiary processing; situation coverage systems |
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The generator of various type of signals for real radio conditions simulation is described. The generator can be useful for communicating devices characteristics check. The random pulses flows generation algorithms for simulation of the not intentional and intentional interferences, using generator are described. Assessment for generated random pulse signals characteristics in comparison with theory are given. Keywords: noise immunity, Rayleigh, Poisson, interfering signal, signal |
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Material authority | |
We present an algorithm for determining the temperature dependence of the volumetric heat capacity and thermal conductivity tensor elements with respect to the anisotropic thermal conductivity of the materials used in the aviation and aerospace technology. The effectiveness of the algorithm is demonstrated by the example of solving the problem of computational experiment data. Keywords: tructural materials, aviation and aerospace technology, thermal and physical characteristics, thermal conductivity tensor of anisotropic materials, inverse problem of heat transfer. |
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Economics | |
The technical and economic analysis of a current state and prospects of development of competitive production of domestic aviation equipment is carried out. The main directions of innovative development of the aviation industry of Russia, including within formation and implementation of federal target programs and creation of a perspective scientific and technical reserve are offered. Keywords: aviation industry, federal target programs, scientific and technical reserve, production, competitiveness |
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The program-oriented approach to budgeting is considered in the paper. Classification of target programs by scale of implementation is carried out. Recommendations about increase of productivity of target-oriented methods of management by economy are offered. This includes the construction of formalized representation of target program and structuring of its lifecycle. Keywords: program-oriented approach, target program, formalized representation, lifecycle. |
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In paper the basic stages of system project`s formation and realization in hi-tech branches of economy are described. Personnel maintenance formation of separate stages realization, as key components of resource maintenance process of system projects are considered. Keywords: hi-tech branches of economy, system projects, human resources |