## Vol 25, No 3 (2017)

**Year:**2017**Articles:**23**URL:**https://journals.eco-vector.com/1991-8542/issue/view/1197

Articles

SYNTHESIS OF OPTIMAL CONTROL ALGORITHMS FOR PROCESS OF INDUCTION HEATING OF STEEL

###### Abstract

This paper considers the task of searching for optimal control algorithm of periodic induction heating process in temperature feedback system. Temperature is measured in one of the points of heated cylindrical steel billet. The criterion of optimality is the weighted sum of integral squared error of temperature field approaching to required distribution and energy costs for heating process implementation. Temperature field behavior is described by Fourier equation with nonlinear boundary conditions taking into account radiation and convection heat losses. Dynamic programming method based on Bellman's optimality principle is used for feedback optimal control algorithm synthesis.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):7-15

PROBLEMS OF INTERSUBJECTIVE MANAGEMENT OF SOCIO-TECHNICAL OBJECTS INNOVATIVE DEVELOPMENT

###### Abstract

The paper deals with the problems associated with the organization of intersubjective management of innovative development of socio-technical objects. New point of view considering innovative development opposite to traditional one is represented. Specificity of intersubjective management that causes social and humanitarian problems is shown. Factors that reason these problems are analysed. All the factors are divided into internal (inherent to the human individuals) and external (generated by the external environment, i.e. so-called STEP-factors - technical, economic, political, social). The significance of the conducted research is defined. Some ways of overcoming the problems are outlined as well. Among them is intersubjective approach towards education, legitimization of intersubjective management integration into the whole management system and promotion of the ordinary people participation in management in the mass media.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):16-31

MONITORING OF TEMPERATURE ANOMALIES IN A MULTI-NITROGEN GROUND OF EXPANSION OBJECTS

###### Abstract

Monitoring of the state of natural and man-made objects located in the northern territories of the country is an actual scientific and practical problem. The article presents a methodology for monitoring temperature anomalies in permafrost soils of extended objects. It is built on unique data obtained by layer-by-layer measurement of temperature in each well of the selected site. Determine the layer to which the boundary of thawing of the soil belongs. Then, the temperature models of the wells, the area under test and the corresponding temperature deviations are weighted along the soil layers. Find out the maximum permissible value of the temperature deviation and compare with it the found temperature deviations. In the case of non-fulfillment of the inequality, information is formed each time, which includes the location of the detected temperature anomalies and the corresponding values of the temperature deviations. The efficiency of functioning of long objects located in the permafrost zone increases on average by 7.8 ... 10.1%.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):32-42

EVALUATION OF EFFICIENCY OF AUTOMATED INFORMATION SYSTEMS

###### Abstract

This paper describes problems of estimation of automated information systems efficiency depending of their structure and specificity of current information processes in them. Universal indicators are proposed as indicators for determining technical, operational, technological and economic efficiency of automated information systems. Application of the proposed universal performance indicators may speed up the process of choosing of the automated information systems structure and characteristics. It is proposed to use the indirect integral index of automated information systems efficiency as one of such indicators because it takes into account local and common performance indicators and equally it would display factors of time and quantity.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):43-49

MODELING OF ELECTROMAGNETIC PROCESSES IN A MULTILAYER THREE-PHASE INDUCTION CYLINDRICAL SYSTEM

###### Abstract

The article deals with modeling and calculation of electromagnetic parameters in an induction three-phase system for technological heating and mixing of viscous liquids. The interrelated electromagnetic and electromechanical processes in the multilayer system "inductor-metal cylinder-hollow rotor" are investigated. Specific features of the studied processes are noted. The results of a numerical calculation of electromagnetic fields and the electromagnetic moment of rotation of a rotor in a heated liquid are presented. It is shown that with an appropriate choice of the geometric parameters of the induction system, one can find the required ratio between the thermal power released in the elements of the system and the power going to rotor rotation. The results of the studies are designed to solve the problem of calculating the optimal electrical and geometric parameters of the proposed design.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):50-60

SHAPE OPTIMIZATION OF THE INDUCTOR FOR HARDENING OF SPHERICAL SURFACES

###### Abstract

The article presents the results of experiments to determine the effects of the shape and size of the cross section of the inductor on the uniformity of heating of spherical surfaces for quenching. Two options were considered cross-sectional shape of the inductor: round and square. The size of the cross section of the inductor relative to the diameter of the sphere was varied in the range of 25÷100 %, the air gap of the inductor-sphere and the rotation speed of the sphere remained unchanged. Best to achieve the homogeneity of the heating is determined, the inductor of rectangular cross section with the relative size of the cross section is 55 % of the radius of the heated sphere, the inclination of the plane spiral inductor 30°. The maximum temperature difference is 300°C at its maximum value of 942 °C.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):61-65

MATHEMATICAL MODEL OF SYNCHRONOUS GENERATORFOR SMALL WIND POWER PLANT

###### Abstract

The mathematical model of the wind power plant synchronous generator is intended for the optimal design of its parameters and performance. The simulation object is a low-power synchronous generator with excitation from permanent magnets. The design of an inductor with embedded rare-earth permanent magnets and saturation bridges is used. The basis of the calculation is the numerical simulation of the machine's magnetic field by the finite element method. The magnetic field is modeled separately for no-load, armature reaction and load. The Blondel diagram is used to calculate the operating mode. The longitudinal and transverse armature reactions were modeled by numerical methods. The results obtained allowed us to choose the optimal design of the inductor.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):66-74

ANALYSIS OF HARMONIOUS STRUCTURE OF THE TRAPEZOIDAL PHASE VOLTAGE FORMED BY THE FREQUENCY CONVERTER

###### Abstract

The basic lacks of the sinusoidal and vector modulators applied in modern frequency converters are considered. For the purpose of simplification of technical implementation it is offered to use the modulators which are carrying out trapezoidal pulse-width modulation. Decomposition the trapezoidal phase voltage of the frequency converter in a harmonic series is made. Analytical expressions of the Fourier coefficients are found. The harmonic composition of the phase voltage of trapezoidal form is analyzed. It is shown that quality of output voltage of the frequency converter which is carrying out trapezoidal modulation, corresponds to GOST requirements. Additional advantages of frequency converters with the trapezoidal modulators, consisting in decrease of switching losses of the power transistors and absence of so-called «dead» time are noted.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):75-79

THERMODYNAICS OF NIOBIUM CARBIDE DEPOSITING PROCTSS FROM GAS PLASE

###### Abstract

The results of thermodynamic analysis are presented for the process of niobium carbide deposit consisting of niobium pentachloride gas mixture and methane under low pressure. The methods of niobium сarbide covering deposition on hard-alloyed non-resharpened plates are briefly described. It is shown that reaction of chloride restoration and disproportion in reactive volume occurs as a result of which niobium escapes and interacts with carbon, and then niobium carbide of stehiometric composition forms. The thermodynamic analysis has been carried out with the aim of reaction’s definition having the greatest degree of the reaction’s probability leading to forming of carbide niobium homogeneous covering. Calculation of isobaric and balance constant has been carried on the entropic method based on the equation by Gibbs and Gelmgolz. It is shown that pressure lowering in the reactive volume increases probability of reaction proceeding resulting in forming of niobium carbide covering.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):80-84

OBTAINING EXACT ANALYTICAL SOLUTIONS OF HYPERBOLIC EQUATIONS IN THE HYDRAULIC SHOCK IN THE PIPELINE

###### Abstract

Using integral cosine - transform for the restricted definition area of elliptic coordinate and the Laplace integral transform for the unlimited area changes unilateral parabolic coordinate, it was obtained the exact analytical solution of the hyperbolic equation describing the pressure distribution along the length of the pipeline in time with respect to the motion of a real viscous fluid in the hydraulic shock. It was shown that the process of pressure fluctuation is accompanied by the movement of a hydraulic wave, front in which the pressure surge of the pressure value at the current point up to the pressure of the disturbed flow. After reaching the front hydraulic wave end of the pipeline, closed valve, changing direction of fluid flow with a pressure jump of opposite sign on the at the front hydraulic wave. The oscillatory process of pressure change at any point of the pipeline in time occurs with decreasing amplitude according to the exponential dependence.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):85-97

RESEARCH OF THE HEAT-SHIELDING OF EXTERNAL PROTECTIONS OF BUILDINGS AT THE EMERGENCY HEAT SUPPLY

###### Abstract

It is carried out research of operating modes of system of a heat supply conditions emergency submissions of heat supply from thermal power station. The factors influencing a thermal mode of premises of buildings, having external protections of various design are considered. Safe operation of protections and buildings as a whole is determined not only time full frizzing of walls, but also the period during which on its surface the temperature goes down to a dew-point or admissible difference of temperatures between an internal surface of an external protection and temperature of internal air. The decision of a problem on cooling external walls of buildings is offered at the emergency temperature schedule of work of a heating system. The technique of calculation is developed for speed of cooling of an internal surface of an external protection and temperature on this surface during the set moment of time. The temperature of internal air at which there is a loss of a condensate on an internal surface of protections is certain. Application of the developed technique and schemes of automation of work of systems of a heat supply can increase of energy efficiency and promote of energy saving of buildings at failures in thermal networks.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):98-109

ENERGY EFFICIENT ORGANIZATION OF ELECTROPLATING PRODUCTION AT A LARGE MACHINE-BUILDING ENTERPRISE

###### Abstract

The paper considers the energy saving problem of a typical large machine-building enterprise of limited and single type production. The energy balance is composed of the most energy-intensive process area - electroplating production. The possible technological options of power supply were explored and the most rational option was defined. Decentralized steam supply by mobile steam generators is suggested as power supply for electroplating production.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):110-116

METHOD OF ADDITIONAL REQUIRED FUNCTIONS IN TASKS OF HEAT CONDUCTION WITH VARIABLE PHYSICAL PROPERTIES OF THE ENVIRONMENT

###### Abstract

Using additional required functions and additional boundary conditions in an integral method of a heat balance, high-precision approximate analytical solutions of the task of heat conduction for the infinite plate with variable physical properties of the environment in case of the symmetric boundary conditions of the first kind are received. For finding of the decision into areas 0,05 ≤ < ∞ the additional required function characterizing change of temperature in center of a plate which in view of the infinite speed of distribution of the warmth put in the parabolic equation of heat conduction begins to change right after application of a boundary condition of the first kind is entered. Therefore, the range of its change includes all range of time of nonstationary process and all range of change of temperature. For obtaining the decision in case of small and midget values of time the model with a final speed of distribution of warmth based on determination of the front of temperature perturbation and additional boundary conditions is used. The combination of these two models (with the infinite and a final speed warmth distribution) allowed to gain rather simple look approximate analytical solutions of the complex non-linear challenge (with nonlinearity of the second kind) in all range of time of nonstationary process, practically with the given accuracy rating. Reviewing in both models of additional required functions allows to consolidate the solution of partial equations to integration of ordinary differential equations.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):117-129

SOLUTION OF THE PROBLEM OF CYCLIC CONTANT HEAT CHANGE FOR THE SYSTEM OF TWO PLANE BODIES IN CASE OF DEFORMATION HEAT INITIATION

###### Abstract

By using the integral Laplace transform the analytical solutions are obtained for a series of cyclic heat problems for plane bodies, including the contact heat exchange for the system of two endless plates with thermal resistance in the contact zone for different conditions of external heat exchange. The solution is obtained for quasi-stationary process state by using the conjugation method in the form of the system of two integral Fredholm equations of the first kind. The solution takes into account the cyclic initiation of heat source of plastic deformation of one of the plates, two analytical approaches are used: the method of successive assumptions (takes into account special heat exchange conditions for individual elements of the contact system in an arbitrary cycle) and the coupling method (takes into account the necessary conditions for the formation of a system of integral equations).

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):130-142

CREATING OF A MODEL FOR CALCULATING THE COEFFICIENTS OF THE TEMPERATURE INFLUENCE OF THE ENVIRONMENT ON THE ENERGY CONSUMPTION OF THE REGION BY A THIRD-ORDER POLYNOMIAL

###### Abstract

The paper considers the modification of the existing approach to determining the coefficients of influence of ambient air temperature within the region on energy consumption in the region. The existing approach proposed by the authors of the article [2] is analyzed in which a coefficient depending on the temperature itself is proposed as a mathematical model of the temperature influence, and its variation is described by a piecewise linear model. In contrast to the existing approach, the author proposed to test the hypothesis of using the third-order polynomial as a temperature-effect model. In the course of testing the hypothesis of representing the coefficient of temperature effect in the form of a nonlinear model given by a third-order polynomial, it was established that this approach can consistently replace the piecewise linear model proposed in [2]. As a criterion for the consistency of the model, the determination coefficient R2 was chosen, the values of which were determined at several intervals within the range of the temperature change and are presented in the form of a graph.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):143-148

MODEL OF DISTRIBUTION OF THE DIFFRACTOGRAM OF COMBUSTION PRODUCTS OF SHS SYSTEMS BY THE EXAMPLE «19Si + 17C + 6NaN3 + (NH4)2SiF6»

###### Abstract

The method of azide self-propagating high-temperature synthesis (SHS-As) using sodium azide as a nitriding reagent was used to prepare a nitride and silicon carbide composition from the "19Si + 17C + 6NaN3 + (NH4) 2SiF6" mixture. The phase composition of the synthesis products was determined on an automated X-ray diffractometer ARL X'TRA. X-ray spectra were recorded using Cu-radiation. Using MINCRYST and COD databases, determine the interplanar distance and cell parameters of the synthesized products and compare them with the results of X-ray phase analysis.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):149-153

INVESTIGATION OF THE POSSIBILITY OF INTRODUCING A LEAVING POWDER NICKEL ADDITIVE IN THE COMPOSITION OF THE MATRIX BASES OF Al AND Al-Cu

###### Abstract

One of the priority directions for improving the mechanical characteristics of aluminum composite alloys is the doping of matrix substrates by chemical elements capable of forming a second phase of increased strength. In traditional foundry technologies, as a rule, a ligature method of introducing additional components is implemented, which requires significant preliminary costs. In the present work, the possibility of introducing a nickel doping additive into the Al and Al-5% Cu matrix bases was investigated, and the possibility of introducing nickel into the melt both as a metal elemental powder and as a component of nickel oxide NiO was shown for the first time. The microscopic data, based on the local X-ray spectral analysis, confirm in both cases the production of the NiAl3 target phase, and the results of mechanical tests indicate hardening of the matrix alloys.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):154-160

SYNTHESIS OF DETERMINATED-STATISTICAL MODELS FORM OF A WELDED SEAM FOR ARGON-ARC WELDING WITH A NON-CONSUMABLE ELECTRODE

###### Abstract

In this article, a study is made of the existing deterministic-statistical models of the shape of a weld during arc welding. On the basis of existing models, seam shape models have been synthesized that take into account specific parameters of the argon-arc welding regime. Under experimental verification, using the regression analysis method, statistical coefficients of the models were revealed. An analysis of the error in the models allows us to conclude that they can be used in real welding production.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):161-167

RESEARCH OF DEFORMATION AND HEAT TREATMENT EFFECT ON RESIDUAL MACRO STRESSES LEVEL AND PHYSICAL WIDTH OF X-RAY INTERFERENCE PEAKS IN SHEET ALLOYS AMg5, AMg6, AMg10 and D16

###### Abstract

Residual stresses in sheet metals and alloys effect on parts geometry sizes accuracy, produced by sheet stamping operations. In this research, effect of aluminium alloys AMg5, AMg6, AMg10 and D16 sheet blanks’ initial state and deformation ratio on residual macro stresses and physical width of X-ray interference peaks is experimentally studied. All alloys’ sheet blanks 2 mm thickness were undergone to annealing and alloys AMg10 and D16 were undergone to quenching before cold rolling. It was found that recrystallization annealing after cold rolling does not eliminate completely cold deformation’ effect on residual macro stresses in all considered alloys. Physical width of X-ray interference peaks increases after annealing. Study of coherent dispersion areas sizes and crystal lattice’ micro distortion’ role is performed. Physical width increasing in alloys AMg5 and AMg6 is due to crystal lattice micro distortion, meanwhile in alloys AMg10 and D16 coherent dispersion areas sizes play the most effect on X-ray interference peaks’ physical width at cold rolling.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):168-178

ANALYSIS OF APPLICABILITY OF HYBRID MODELING SYSTEMS FOR PROBLEMS OF DISPATCHING MANAGEMENT

###### Abstract

Calculations of the steady-state regime are carried out, as well as the processes taking place in the simulation of electromagnetic and electromechanical transients in a small-scale test power system in the PowerFactory software and in the hybrid real-time power system simulator. In steady-state conditions, the voltages and active and reactive power flows were within the permissible errors. In the simulation of various kinds of disturbances, the algorithm of the hybrid real-time power system simulator has proved to be more accurate than the electromechanical transient calculation mode in the PowerFactory program and is almost identical to the method for calculating electromagnetic transients. However, due to the presence of an analog component in the complex, the speed of operations is significantly increased, which expands the range of tasks solved by the hybrid real-time power system simulator. High efficiency of the complex allows us to conclude that it is applicable in various power companies.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):179-181

MODELING OF FUNCTIONING STEADY-STATE MODES OF GAS COOLING SYSTEM

###### Abstract

The article is devoted to the development and comparison of static models of the gas cooling system. As initial data, instantaneous values of plant operation technological parameters were used, fixed for six years with a two-hour period. In this article, we made preliminary selection of data corresponding to the operating mode. We also show implementation results of models based on: regression analysis, solving of heat transfer equation, the nearest neighbor algorithm. The error of the obtained models is estimated.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):182-187

DYNAMIC DETERMINATION OF QUANTITY AND CAPACITY IN THE FUEL TANKS

###### Abstract

An approach is proposed for determining the amount of fuel in fuel tanks based on primary production data. A mathematical model of the amount of fuel in tanks is used. The use of the model is applicable for calculating the amount of fuel in static states, such as operations to remove full-scale residues. With multiple operational calculations of the mass of fuel with a small time interval (if it is actually changed, for example, as a result of filling or evacuation out the tank), the resulting mass values can be interpreted as the fuel mass flow in the pipeline, i.e. As an alternative to the meter reading. The method is of interest for heat-and-power engineering plants, since it allows simulating fuel consumption in tons (mass) and in tons of equivalent fuel (energy value).

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):188-191

USE OF ADDITIVE TECHNOLOGIES FOR PILOT STUDIES OF METHODS OF NONDESTRUCTIVE CONTROL

###### Abstract

The attempt of identification of defect in a solid body by means of methods of nondestructive control (polarizing and optical methods) is executed. Pilot studies of the intense deformed condition of natural objects with use of the flat and spatial models made by means of the additive technologies containing (defects) of various volume in a cavity are conducted. Modeling of defect in a solid body of a cubic form under the influence of monoaxial loading in the multipurpose Simula Abaqus complex is executed. Various cases of an arrangement of defects in a solid body are considered. Results of the numerical calculations executed in the program Simula Abaqus complex are given.

**Vestnik of Samara State Technical University. Technical Sciences Series**. 2017;25(3):192-197