Другие журналы

scientific edition of Bauman MSTUSCIENCE & EDUCATIONBauman Moscow State Technical University. El № FS 77  48211. ISSN 19940408
# 10, October 2013
Machine Building and Engineering Science
A design technique of manufacturing bellshaped details
# 10, October 2013 DOI: 10.7463/1013.0636230 In this paper the authors consider a design technique of a twostep manufacturing process of a bellshaped detail with the use of overlapping of operations at one step. Those operations were drawing, pressing and expanding. Dependences for determination of the workpiece dimensions of the first step of drawing which are the diameter and thickness of a round workpiece, were presented in this article. The authors give recommendations on determining dimensions of a cylindrical cup produced at the first step of drawing, namely the diameter and height of a cylindrical cup along with the maximum and minimum wall thicknesses. An example of production engineering of a sheetmetal stamping for manufacturing a specific bellshaped detail, using an overlapping of operations mentioned above. Results of experimental verification of the manufacturing process developed according to the proposed method were also presented in this paper.
Investigation of sensitivity of MIG/MAG welding of a root weld to geometrical disturbances of the groove assembly
# 10, October 2013 DOI: 10.7463/1013.0631684 This article provides a comparative analysis of requirements for groove preoperation before automatic welding. It was mentioned that the required accuracy of edge preoperation could hardly be achieved under field conditions. A review of modern methods of welding adaptation was provided. Influence of groove geometry disturbances on formation of a root weld in the process of automatic MIG/MAG welding was investigated through a set of experiments. It was determined that critical values of a root gap and misalignment disturbances depended on the mean root face value. Recommendations on accuracy of assembling and edge machining were provided.
Development of a model of ultrajet instant diagnosis of materials
# 10, October 2013 DOI: 10.7463/1013.0604128 This article deals with application of ultrajet diagnosis of materials, which is one of the most promising and complex methods allowing one to estimate durability of materials instantly under various conditions. A review of existent mathematical models which allow one to evaluate the depth of a honeycomb originated on the surface of a material as a result of ultrajet influence. Requirements to the ultrajet interaction model and the material being diagnosed were determined. On the basis of these requirements a model which could be used in the technique of the ultrajet instant diagnosis was proposed.
Constructional Material Processing in Machine Building
Estimating efficiency of interrupted cutting on the basis of change pattern in heat density of the process
# 10, October 2013 DOI: 10.7463/1013.0623113 Calculation models of changes in heat density of an interrupted cutting process and their connection with technical and economical processing indexes were considered in this paper; these indexes allow one to determine changes in cutting tool life and in working efficiency, depending on kinematical features of the process. Manufacturing operation and kinds of work such as edge cutting, abrasive and surface plastic deformation with cyclic change of mode parameters were presented. During investigation of these operations or their development at the stage of process design it is rational to apply the specified models.
Power Machine Building, Metallurgical Machine Building and Chemical Engineering
Shaping of inlet ports of a diesel for conditions of high pressure charging and high pressure differentials between a collector and a cylinder
# 10, October 2013 DOI: 10.7463/1013.0617277 In this paper the authors present results of shaping a piston engine’s inlet ports. The “Large Particle” CFD method was used for simulation of a flow and estimation of the effective flow area. The investigated flow modes are characterized by high density of the incoming charge and a significant pressure fall. Diagrams of influence of geometry features on channel capacity are also given. A spatial profile of the engine’s inlet ports, including an axisymmetric part near the seat, was considered along with the diameter and location of the intake popped valve. Recommendations were given on optimal shaping of the intake ports for the promising ZEngine.
Mathematics and Mathematical Modeling
Thermophysical model of biotissue and its numerical implementation
# 10, October 2013 DOI: 10.7463/1013.0645537 An adaptive mathematical model of bio tissue for heat calculations was introduced; this model takes into account hemoperfusion, heat exchange with surrounding air and other specific for living tissues internal heat sources which are calculated from boundary conditions of a steady state. Discretization procedure for this model was described; results of numerical simulation by the example of single and double layer biotissue were presented. In order to validate the discrete model corresponding analytical solution for a particular case was obtained. It was shown that the existent Pennes model is a special case of the proposed model. Possible application domains were also discussed in this paper.
Mathematical simulation of dielectric properties of polymerceramic composite materials, using the asymptotical averaging method
# 10, October 2013 DOI: 10.7463/1013.0623343 In this paper, the authors presented a mathematical model for calculating effective dielectric characteristics of complex structured composite materials influenced by an external alternating electric field. An asymptotic investigation of electrodynamic differential equations with fast oscillating coefficients was carried out. A local electrodynamic problem on the composite’s “periodicity cell” was formulated. An effective complex permittivity of composite materials with various volume fractions of the finedispersed ferroelectric ceramic inclusions was calculated by the finite element method and the biconjugate gradient stabilized method. The authors analyzed frequency dependence of dielectric characteristics and dielectric loss tangent of composite ceramics. The obtained results are good congruous to experimental data.
Discrete Markov model of a doublesided battle of numerous groups
# 10, October 2013 DOI: 10.7463/1013.0617171 The purpose of this work is to design a model of doublesided battles of numerous groups on the basis of discrete Markov processes. Mathematical relations which allow one to calculate probabilities of fighting strength preserved on each side during the battle and at the end of one. The present study addresses the question of influence of various factors on the battle outcome and main indicators of the mission. The proposed model may be used not only for development of new weapon models and defense equipment but also for estimation of their adequacy for execution of assigned missions.
Solving terminal control problems for affine systems
# 10, October 2013 DOI: 10.7463/1013.0604151 In this paper a new approach was proposed to solve terminal control problems for affine systems. This approach is based on transformation of a system under consideration to a quasicanonical form system. Moreover, it was assumed that all subsystems of the canonical form are twodimensional. A sufficient condition for existence of a solution for the terminal control problem was proved. A numerical procedure was also proposed to construct a solution of the terminal control problem for affine systems which are equivalent to systems of the quasicanonical form with twodimensional subsystems of the canonical form. An example was given to illustrate the proposed approach.
Approximation of values of an exponential function
# 10, October 2013 DOI: 10.7463/1013.0604020 In order to obtain quantitative results in the theory of Diophantine approximations one uses functional linear approximating forms which have sufficiently high order of zero at z = 0. Such forms are constructed either by means of the Dirichlet principle or effectively. In this article, by means of effective construction of approximating linear forms, we obtain a low estimate of the modulus of a linear form in the values of an exponential function in different points of an imaginary quadratic field; numerators of these points are roots of unity. Precise estimates, with respect to the height, were obtained with computation of corresponding constants. The proposed construction could be used for obtaining analogous estimates in values of generalized hypergeometric functions.
Aeronautical and Rocket Space Engineering
Torque in the thrusters with anode layer
# 10, October 2013 DOI: 10.7463/1013.0656749 Effect of the torque in the thruster with anode layer was considered. It was shown that the mechanism of appearance of such torque is associated with the azimuthal deflection of ions in the accelerating channel of an engine as it moves in the radial magnetic field. Dependences between the angular acceleration of a device and the strength of magnetic field for different thruster’s operating modes, different working substances and massdimensional characteristics of the spacecraft were obtained. It was also demonstrated that this torque could have a significant impact on the stabilizing system in cases of longtime operation. The remedy for harmful influence of the azimuthal deflection of ions on the spacecraft’s rotation was proposed.
Stationary plasma smallpower thruster
# 10, October 2013 DOI: 10.7463/1013.0640392 In this paper results of experimental studies of integrated characteristics of a laboratory model of a stationary plasma thruster of new generation, which is α40, calculated at the rate of total power consumption equaling 150 W were presented. Integrated parameters of this model, such as thrust, discharge current, specific impulse and efficiency obtained at testbenches of MSTU MIREA and OKB "Fakel" were almost identical. Thus, at the input power of ~150 W, voltage of 210 V, consumption of xenon of 0,7 mg/s, thrust appeared to be 9.4 мN, the anode specific impulse of thrust was equal to ~1370 s, and the anode efficiency, taking into account the power consumed by magnetic coils, equaled to 41%. Another mode with a bigger thrust (9.7 мN) but with a smaller specific impulse (1240 s) at the same input power was received at the consumption of xenon of 0.8 mg/s and voltage of 190 V. Efficiency was about 40%. The semiangle of divergence of a plasma beam was equal to ±25 °. Predicted life expectancy was approximately 2500 hours. The data provided in the paper showed that α40 is more efficient than any known analogues.
Analysis of design features of largescale inflatable solar energy concentrators
# 10, October 2013 DOI: 10.7463/1013.0618788 All these approaches were illustrated by an example of mirror concentrating systems. Special attention was paid to design features of inflatable (pneumatic) solar concentrators and approaches that provide high geometric accuracy of a reflecting surface form when it deploys, fixation and shape stability during operation. It is of particular interest for design, manufacturing and operation of largesized mirror concentrating systems for hightemperature solar power plants for both ground and space applications. Main design features of inflatable structures are related to the fact that they need to be pressurized for their deployment. But it is also necessary for maintaining (saving) the shape of such structures, which requires presence of structural elements under constant internal inflation pressure and, generally, in a strain state. A number of approaches to minimize problems caused by these design features were discussed, such as use of thermosets, introduction of additional structural elements, etc. Some approaches to design of largescale space structures were considered in this paper.
Controlling angular movement of a small spacecraft
# 10, October 2013 DOI: 10.7463/0613.0574636 This authors briefly describe a promising activepassive control system of angular movement of a small spacecraft (by an example of nanosatellites) based on a construction with a gravitational stabiliser and microthrusters. Operating modes of the microthrusters’ control block were proposed; they were passive mode, initial stabilisation mode, stabilisation and orientation modes. Formulas for determining the required number of microthrusters for a smallsized spacecraft in each mode were presented. The main advantages of the proposed activepassive control system of angular movement and applications of a smallsized spacecraft equipped with this system were also described.
Instrument Engineering, Metrology and InformationMeasuring Devices and Systems
Positional laser measuring systems with feedback on intensity of laser radiation
# 10, October 2013 DOI: 10.7463/1013.0623318 This article deals with increase in accuracy of positional (photoelectric) laser measuring systems. Amplitude instability of laser radiation represents the most significant part of total measurement error. A method for introducing feedback on intensity of laser radiation into the structure of a laser measuring system was proposed; this feedback allows one to stabilize the measuring system parameters. Introduction of this feedback was provided by mounting an additional photoreceiver which registers the reflected laser beam; a signal from the photoreciever is used for correction of information received from the main measuring channel.
Mathematical model of aerial photosystem based on photosensitive devices with charge transfer transfer
# 10, October 2013 DOI: 10.7463/1013.0619667 This paper considers a mathematical model for estimating resolution measuring properties of an aerialphotosystem developed on the basis of photosensitive devices with charge transfer. The proposed mathematical model which implements an analytical method for estimating resolving power of aerial photosystems based on the theory of linear optoelectronic system allows to obtain assessments of resolving power for various types of aerial photosystems with consideration for their conditions of use.
Quantitative gas analysis of complex multicomponent mixtures
# 10, October 2013 DOI: 10.7463/1013.0615247 This paper deals with a comparative analysis of algorithms for regenerating concentration of gases in complex multicomponent mixtures by means of multispectral laser measurements. Signal processing methods for complex multicomponent mixtures based on the Bayesian assessment of a solution and the projective method are described in this work. The results of the mathematical simulation show that usage of the Bayesian assessment for a solution of the laser gas analysis system of equations allows to solve a problem of regenerating concentration of gases for complex multicomponent mixtures with smaller errors than usage of the projective method.
Development of a complexation method for information of multiparameter nondestructive control for detection of internal defects in complex structures
# 10, October 2013 DOI: 10.7463/1013.0615195 Defects in multilayer constructions made of composite polymeric material, for example, defects that occur when the material discontinuities, reduce their performance. Considering a high cost and complexity of manufacturing such products from polymeric composite materials, as well as a high cost of products in which these polymeric items are used, detection of defects during manufacture and exploitation of products appears to be a very crucial task. Therefore, creation and implementation of equipment and methods for reliable detection of defects within a large application domain is reasonable. This paper describes main principles and methods of complexation of information of multiparameter nondestructive control with the purpose of increasing reliability of detection of defects in complex structures by the example of structures made of polymeric composite materials. The results of developing a method of complexation of nondestructive control methods addressing the formulated problems are presented in this work. These results are based on estimation of the telescoping effect and building a multidimensional analogue of the inverse probability method.
Approximation of the air resistance law of 1943
# 10, October 2013 DOI: 10.7463/1013.0609269 The author proposes a method of fitting the Siacci air resistance law which was practically approved to the law of 1943. This law is widely used in the Russian Federation for computing parameters of trajectories of projectiles but doesn’t have an analytic description up until today. In this work a corrective multiplier for the Siacci function was introduced; this factor represents analytical approximation of a sequence of discrete compensation factors in the form of a continuous dependence on the projectile speed (Mach number). As a result, computation of the trajectory parameters with the use of a PC is simplified. An example of using the approximation is also provided.
Informatics, Computer Science and Management
Automatic synthesis of the helicopter programmed motion along the horizontal line
# 10, October 2013 DOI: 10.7463/1013.0660675 For fourdimensional model describing the helicopter motion along a given horizontal line the problem of automated synthesis of programmed motion is solved. This solution provides a helicopter motion from a given state of rest in the given state of rest. Time to perform the maneuver is not set. The considered helicopter model is a control dynamic system, which is not a flat system. For such systems general approaches to the terminal problem solution are presently unknown. To solve the terminal problem two approaches are applied. The first approach is based on the use of finite symmetry, which converts the initial conditions of the problem in the final conditions. The use of such symmetry can reduce the number of final conditions. The second approach is based on the use of covers and consists in the construction of a special mapping, which for two given dynamic systems surjectively maps the set of solutions of the first system in the set of solutions of the second system. The programmed motion in this case can be found as the solution of two related specifically posed Cauchy problems for these dynamic systems. The resulting programmed control is a piecewise continuous function of time.
Performance and effectiveness of hardware implementation of stream ciphers based on generalized cellular automata
# 10, October 2013 DOI: 1013.0624722 In this article data on performance and effectiveness of the GRACES family of stream ciphers based on generalised cellular automata and expander graphs were discussed. Altera FPGA was used as a platform for hardware implementation. The performance of GRACES stream ciphers was compared with the performance of stream ciphers that had won the eSTREAM competition. According to the performed tests, the performance of the GRACE–S family of stream ciphers significantly (up to 60 times) exceeds the performance of the bestknown stream ciphers.
Application of matched filtering for processing ultrawideband signals
# 10, October 2013 DOI: 10.7463/1013.0623000 The author considers a possibility of using matched filtering of UWB signals. Maximum achievable characteristics of UWB systems make them promising for many application domains such as data transmission systems, medical systems, security systems, radars, etc. Processing is possible with the use of special filtration devices created on the basis of irregular transmission lines with the Twave, in particular, on the basis of matched filters, which is the main topic of this paper. For a UWB sounding signal duration is much shorter than duration of a signal reflected from the target; therefore, it could be taken as a sampling period. In this case, application of preliminary matched filtering of the reflected signal, followed by traditional processing, is possible.
Structural models of product assembly
# 10, October 2013 DOI: 10.7463/1013.0622946 In this paper the author proposes a new approach to description of mechanical linkages which determine a certain position of machine’s or device’s elements in a technical system. The location relation that exists between parts of any machine or device was considered to be manyplaced and is presented as a hypergraph. A mathematical description of the product assembly sequence was presented as a contraction of vertices of the hypergraph. Necessary conditions of contractibility for this type of graphs were proposed. A new structure  a lattice of all ssets  was introduced. It was shown that this lattice could be used for generation of various design decisions at the stage of technological preparation of assembly production.
Random access to telemetry data files compressed with deflate algorithm
# 10, October 2013 DOI: 10.7463/1013.0616065 Telemetric information recording systems are usually designed for display, preprocessing and record of incoming data stream to any kind of storage media in real time In case a computer is part of a system its HDD or flash drive could serve as a storage device. In that case, the data stream is stored as an ordinary file. Telemetry data recording process can take for a long time, while the amount of recorded data could grow up to tens of gigabytes or even more. It looks reasonable to compress these data while saving them to a storage media and keep them there in archived files. Later when postprocessing is applied to the recorded data, it is often interesting to work with particular fragments of a record, while fast moving of the “read pointer” within a compressed file and extracting of particular data blocks is required. In other words we need to provide fast readonly random access to the compressed data. OS “builtin” and/or wellknown compression software utilities (such as Zip) generally have the same disadvantage: they have to decompress archive file from the very beginning up to a specified point. It is impossible to start unpacking a file from an arbitrary position due to the fact that the deflate algorithm that is in the core of these utilities always needs to know some prehistory in the sequence of uncompressed bytes to proceed with decompression. It is of no importance for small files, because unpacking routines are fast and highly optimized, plus unpacked data can be easily cached. In the meantime, for large telemetry records the problem remains. In this paper the author proposes an effective method that allows to make readonly random access to the packed data faster. This is achieved by inserting some supplementary information into the archive file while it is being recorded. This extra information allows starting decompression from a set of "reference points" within the archived file, but not only from zero index byte. Required modifications in the famous zlib compression library are described.
Terminal control of processes in chemical reactors using orbital linearization
# 10, October 2013 DOI: 10.7463/1013.0612563 The authors consider an affine third order system which describes action of a chemical batch reactor with a ternary working mixture. The terminal control problem for this system with restrictions on state variables was investigated. Solution to this problem is based on the orbital linearization approach by which the original problem is transformed to a terminal problem for a nonstationary secondorder system in a canonical form. For the transformed terminal problem conditions for solution existence were obtained; a method of obtaining this solution was also proposed. Operability of the proposed method was illustrated by mathematical simulation.
Global optimization with the use of a biogeographybased method
# 10, October 2013 DOI: 10.7463/1013.0605836 This article deals with a promising global optimization method that is a method of biogeography (BBO). Efficiency of this algorithm and its implementation was demonstrated by the example of the known complicated minimization problem of the multidimensional Rastrigin function. Integration of implementation of the biogeography method developed in MATLAB with PowerFactory software of DlgSilent was considered; PowerFactory software was used to calculate total power losses in the electric circuit being under consideration. Efficiency of the biogeography method for solving optimization problems of IEEE9 and Kuban’s power networks was investigated with the use of MATLAB BBO + PowerFactory. By optimizing a set of compensators and their physical layout, realpower losses in the specified networks were successfully reduced by 9.2% and 2.5% respectively.
Estimation of computational complexity of the fast numerical algorithm for calculating vortex influence in the vortex element method
# 10, October 2013 DOI: 10.7463/1013.0604030 In this paper the authors consider a fast numerical algorithm for calculating convective velocities in the vortex element method. This algorithm is based on derivation of a tree of rectangular regions which contain vortex elements. Influence of parameters of the fast method on computational complexity of the algorithm was analyzed. The number of arithmetic operations required for calculating velocities of all vortex elements was evaluated for modeling an evolution of vortex motion in an ideal incompressible liquid. This theoretical estimation is in good agreement with the results of the numerical experiment. The developed approach could be useful in practice because it allows to select optimal values of the algorithm parameters a priori.
Mechanics
Method of relaxation analysis of contact interaction between a fuel element and a cell of a spacer grid
# 10, October 2013 DOI: 10.7463/1013.0654596 Development of a method for calculating relaxation of a contact between a fuel element and a spacer grid cell is a necessary condition for solving complex deformation problems of fuel assembly under intensive temperature and neutron fields. Due to relaxation of contact interaction the fuel element can slide in the spacer grid cell; this results in decreasing stiffness of overall assembly and its deformation. A method for calculating relaxation of contact interaction between a fuel element and a spacer grid cell based on the finite element method and the Schwarz alternating method was proposed in this work. Calculation of relaxation with the use of the proposed method will allow to estimate operation time of a fuel element till its sliding, and also to determine the disability criterion of fuel assembly.
Modeling of nonstationary internal heatmasstransfer in heatshielding structures by the threedimensional finiteelement method
# 10, October 2013 DOI: 10.7463/1013.0606069 In this article the authors propose a finiteelement method for calculating nonstationary heatmasstransfer 3D problems in heatshielding structures made of composite materials with consideration for thermodecomposition and filtration of gases in pinholes. Specialized software that implements the numerical finiteelement method for solving the problem of internal heatmasstransfer in 3D elements of structures made of composite thermodestructive materials was developed. In this paper the authors also present results of testing the developed method and software that illustrate working capacity of this method and its applicability to solving investigation problems of nonstationary heating modes of heatshielding structures.
Hysteresis development of selfoscillations with a limited artificial gas cavity formed in a hydraulic line
# 10, October 2013 DOI: 10.7463/1013.0604048 Artificial cavitation occurs in a hydraulic line as a result of gas feeding either into a separation zone behind bluff bodies, or directly from the wall jet in the liquid flow line. The resultant attached cavity is often unstable, so the system is set for a state which is characterized by oscillations of pressure and flow phases. This process is greatly enhanced with the proviso that the cavity is closed by hydraulic resistance established downstream of the gas injection site. A characteristic abrupt increase in the frequency of oscillation with a monotonic increase in the flow rate, and the same sharp decrease in frequency at lower flow rates could be identified as special features of the process in some working modes. The authors propose an explanation of the experimentally identified hysteretic nature of development of selfoscillations in the hydraulic lines with a limited artificial gas cavity at the output.
Tensor nonlinearity of media that show significant difference in resistance to tension and compression
# 10, October 2013 DOI: 10.7463/0513.0571202 Tensor nonlinearity as a phenomenon brings together many wellknown effects inherent in the specified materials, including grey cast irons study of which can be found in works by M. I. Leonov and his disciples. Processing of test results and description of properties of such media, with a very great difference in limiting deformations, is a complicated problem. In this work it was shown that the best way to solve this problem is to use V.V. Novozhilov’s theory about connection of stress and strain deviators with specified experimental results; these results allowed to improve the method of determination of material functions within the range of all ultimate deformations of simple tests. It was possible to achieve the latter with the use of “extrapolation” of initial data up to the ultimate deformation of compression. The model created by this method reflects the effect of dilatancy in a generalized sense more accurately, revealing the essence of tensor nonlinearity. It was also shown that the accumulated deformation of loosening can be chosen as a criterion of strength.
Behaviourial Sciences
Psychological analysis of professional activity of an elite specialist in the sphere of engineering and technology
# 10, October 2013 DOI: 10.7463/1013.0589274 This article presents results of a structuralfunctional analysis of professional activity of elite specialists in the sphere of engineering and technology. The purpose of the empirical research was to study the system of professional activity of elite specialists in the sphere of engineering and technology: motivations, objectives, conceptual models of activity, programs of professional activity, nature of decisionmaking and personal behavioral qualities. The object of research was professional activity of elite specialists in the sphere of engineering and technology. The subject of the research was structuralfunctional characteristics of the system of professional activity of elite specialists in the field of engineering and technology. The main research method was an expert survey. The respondents who took part in the survey were elite specialists of a technical activity profile.
Appendix History of Progress
7748211/636161 Kilby Jack Saint Clair (his 90th anniversary)
# 10, October 2013 УДК: 929 A brief review of main works and achievements of Jack S. Kilby is presented, outstanding US inventor, the author of more than 60 patents, awarded in 2000 the Nobel Prize in Physics for his basic work on information and communication technology, one of the founders of the first integrated circuit. They also developed the first thermal printer, miniature calculator with builtin thermal print head and the experimental work carried out to facilitate the organization of production of integrated microelectronics in the United States. Information is given about the parents J.S. Kilby, the interesting facts of his life and work, including details in school, his hobbies amateur radio, military service, university education, working for miniaturization of electronics in the laboratory Centralab, Texas Instruments Incorporated and its patent dispute with Robert Noyce, inventor of the other integrated circuits. Kilby described contacts with colleagues, his awards and to memory of Kilby.



