Vol 13, No 5-4 (2014): Special Issue

In article results of determination of eigenfrequencies of a design of a searchlight of an electric locomotive of the VL series by means of program system of the final and element analysis of ANSYS are stated. The solid-state model of a searchlight having physics and technology parameters of components of a design and the geometrical sizes of a real searchlight was developed for the analysis of vibrostability of a design. As a light source of a front lamp the incandescent lamp and light-emitting diodes were used. Thus for a light-emitting diode the boss from the ceramic material preventing thermal deformations of a substrate was designed. The quantity of light-emitting diodes was chosen, proceeding from lighting requirements to illuminants on the Russian railroad. The analysis of solid-state models of the searchlight using as a light source the incandescent lamp and light-emitting diodes, showed that the searchlight design with light-emitting diodes has weight on 900 grams bigger than a searchlight with the incandescent lamp. The received sizes of eigenfrequencies were compared with frequencies of periodic vibrations which are tested by the rolling stock. For frequencies of vibrations, possible on railway locomotives, deformations of two designs of a searchlight which showed were defined that shortcomings are inherent in both designs. When using as an incandescent lamp light source eigenfrequencies of a design promote destruction of a flask of a lamp, both on top, and at low frequencies of the fluctuations inherent in a range of vibrations of the locomotive. In case of use of light-emitting diodes in a searchlight nature of deformations of a design indicates the need of reduction of its component weight at preservation of necessary rigidity. The carried-out analysis allowed to reveal the directions of development of a design of the searchlight, vibrostability of a searchlight providing increase with a LED light source: application of edges of rigidity and facilitating grooves.

The possibility of the employment of reference specimens hardened simultaneously with the parts has been examined for the hydroblasting influence estimation on the parts with concentrators endurance limit on the example of hollow cylindrical parts made of steel 40 with circular cuts of semicircular profile with the radius 0,3 mm. The investigation has shown that the difference between residual stresses values found by calculating and experimental methods doesn’t exceed 8% in smooth specimens, in specimens with cuts – 6%. Under the hydroblasting influence on the endurance limit estimation in conditions of bending in the case of symmetric cycle for hollow cylindrical specimens made of steel 40Х with cut of radius 0,3 mm it’s been established that the employment of residual stresses distribution calculated by the initial deformations of reference specimen let predict the specimens endurance limit increase under stress concentration conditions to an approximation of 8%. It has been shown that it’s reasonable to use the average integral residual stresses criterion calculated through the dangerous section surface layer thickness equal the non-propagating fatigue crack critical depth for the prediction of the endurance limit increase of hardened by hydroblasting specimens made of steel 40 with stress concentrators.

This work is devoted to the two methods of modeling porous material. Flow characteristics and, accordingly, the viscous and inertial coefficients for the models of porous materials consisting of spherical particles were obtained by calculation. On the basis of these data conformity assessment of flow characteristics for models of porous materials consisting of spherical particles of arbitrary filling and exactly the same on the geometrical dimensions of the flow model in accordance with Darcy's law was carried out. The data thus obtained were then used to estimate the energy dissipation due to viscous friction in the flow of fluid through the porous body. As a result reached the following conclusions. Firstly, in the absence of information about the viscous and inertial factors that determine the performance curve, data rates with sufficient accuracy can be obtained by calculation in the medium Ansys CFX for periodic fragment of the porous body. Secondly, there is a satisfactory agreement between flow performance for porosity γ≥0,1601 obtained in the medium Ansys CFX for periodic fragments of porous bodies and flow model in accordance with Darcy's law.

The article describes the geometric characteristics and features of technology of constructive elements of welded, glued and brazed honeycomb panels used in sound-absorbing constructions channels air intakes and engine casings. Discusses the advantages and disadvantages of various methods for obtaining the perforation drilling electric discharge method: a method of punching sheet at press. Analyse the advantages and disadvantages of each method. In the technique and the dependences for determination of harvesting and the perforation zone boundaries, as well as forming process diagram of perforated paneling. The managing foiling program is developed to meet the geometry, kinematics of the punch press, mechanical characteristics and mathematical model of process of formation. This technique allows you to significantly reduce the number of signs of rejection of the process. One of the most important problems of forming plating method of covering is the uneven distribution of deformations on the surface of the workpiece. To solve this problem, the proposed method of reducing inequality deformation along the contour of the workpiece from the special inserts installed in the press.

Experimental studies shows that the main parts - the shaft and the disks of gas turbine engines, working in the conditions of low-cycle fatigue and durability, have a durability far exceeding the resource identified by calculation based on the hypothesis of linear summation of damage. Therefore, further clarification is needed calculation methods, allowing greater use of the reserves of strength parts. The performed research studies the influence on the durability of the increasing duration of zero cycle of loading samples with a period of T=200 s. and the restraint at the maximum and minimum levels: Dtmax=120 s. and Dtmin=60 s. The studies were performed on a standard round specimens with the diameter of the working area of 7.5mm. Shown that when you restrain a loading there is in the material proceeds relaxation process, combined with a deforming cyclic hardening and increasing of the plastic deformation. It was found that the hypothesis of a linear summation of static and cyclic components of the damage in the conditions of low-cycle fatigue and long-term strength is not confirmed. The increasing of the restraint in the loading cycle under the load to Dtmax=20 s. or more leads to a significant increase - up to 94 % of the static component of damage. The research results obtained during cyclic and repeated static loading, helped to confirm and substantiate the existence of a previously unknown “Effect of cyclic hardening materials”, due to the duration of the maximum load in the cycle of loading.

The possibility of effective efficiency increase of a complex cycle gas turbine with intermediate heating is considers provided that effective efficiencies of simple and complex cycles are equal, the degree of gas heating at the second stage is lower than that at the first one and the degree of increase of pressure the simple cycle is optimal in terms of effective efficiency (economic). The economic degree of increase of pressure is determined as the function of the degree of heating at the second stage, as it provides the maximum of work increase in the complex cycle compared with that in the simple cycle. The effective efficiency of the complex cycle with the selection of air for intermediate combustion chamber cooling is found by summing up the effective efficiency of the simple regenerative cycle for the part of air, selected on cooling, and that of the complex cycle with intermediate heating of the other part of the air. It is found that the effective efficiency of the complex cycle with the selection of air for intermediate combustion chamber cooling and its regenerative heating is higher than that without the selection of air and the effective efficiency of the complex cycle as well as the work of this cycle reaches its maximum at economic the degree of increase of pressure in the simple cycle.

This paper presents the results of numerical and experimental studies of heat transfer of swirling flows in channels and cyclonic vortex tubes using as a working medium of air and superheated steam. The research results of the calculation depends on the number of elements of the computational domain and on the time step. The experimental data were compared non-adiabatic of the vortex tube in air and water vapor. Numerical study of conjugate heat transfer vane turbine with two integrated eddy energy separators with superheated steam as a coolant. Given flow characteristic of the blade, the dependence of the cooling efficiency of the coolant flow and temperature distribution obtained in the material of the blade.

The article presents the results of the development chamber thruster in the perspective oxygen-hydrogen fuel. Was established experimental model, whose main element is the chamber body, taken from the production engine and newly developed mixing head comprising a spark plug, fuel injectors, fuel manifolds, fittings for supplying fuel components, fittings for the pressure measurement. Ignition of the fuel mixture when starting chamber is electric plasma method. Fire tests were conducted camera manufacturer in terrestrial conditions on the experimental setup, which allows to measure the thrust, pressure in the combustion chamber and fuel reservoirs, determine the cost of fuel components. The test results are presented in the form of values of thrust, specific impulse, the coefficient of specific impulse at different total fuel mass flow and the fuel components ratio (different ratios of excess oxidant), suggest the achievement of acceptable energy characteristics. During the tests also confirmed the launch of a reliable chamber in a wide range of variation of the coefficient of excess oxidant confirmed efficiency of the engine during long hot work.

The result of this work was the creation of the chamber thruster on the perspective oxygen-hydrogen fuel. In the process of designing the used ANSYS CFX system, which was implemented mathematical model of homogeneous multicomponent working body with the mixing and combustion. The calculations were performed on a supercomputer "Tornado" in South Ural State University. The simulation results of the first version of the chamber revealed a non-functional due to the high temperatures in the area of structural elements (external cooling was not provided), and therefore it was decided not to make this chamber. In the process of further computational studies chamber design being modified as long as it was not possible to achieve high combustion efficiency with the presence of structural elements near the zones with temperatures not exceeding the maximum allowed operating temperature of the material. Chamber manufacturer has passed fire tests, which confirmed its performance during long inclusions and showed acceptable power characteristics. It was also a satisfactory agreement between the experimental data with simulation results. Thus, the use of numerical modeling would eliminate the traditional to create new chambers long and costly phase of the comparative tests.

Existing cooling technology of cylindrical aluminum ingots don’t provide the same speed of the temperature in all parts of the ingots. The most appropriate use for cooling of ingots special camera. Existing calculation methods and modes of cooling, which take into account the geometric characteristics of the charge and a cooling chamber, and would provide the same cooling rate in all parts of the bars are missing. Therefore, the authors addressed the issue of mathematical modeling of the process of cooling aluminum ingots on the basis of the regulated convective heat transfer. When developing mathematical models were formulated assumptions, mathematical and physical formulation of the problem. The mathematical model included the analytical model of heat transfer in the system aluminum ingots - cooling air, the system of differential equations, initial and boundary conditions. A mathematical model has allowed to carry out an analytical study of the cooling process with constant and variable operating conditions and design factors such as the speed of the cooling air, the diameter of the bars and the height of the channel between the bars. An analytical study has allowed to formulate the algorithm, providing a nominal speed of each cooling of the ingot in a horizontal row by controlled cooling. To prove the validity of the analytical model was performed experimental study. The discrepancy between experimental data and analytical values averaged 34%.

This paper presents the proven analytical apparatus for determining the complex stress state in the material of the linear part -main pipeline with stress corrosion cracking in the form of fine crack colonies. The critical stresses are defined and an analytical dependence for calculation of the allowed internal pressure for the damaged pipeline, not satisfactory to strength conditions is received. The above calculation model of stress state is different from their counterparts in that it is not limited by standard methods based solely on the weakened section, and takes into account the stress concentration in the surface defect zone, which has a positive effect on the accuracy of estimated parameters. Introduced additional conditions during selection of permissible stresses ensures the correctness of strength calculations, especially in cases where there are corrosion cracks with relatively large depth in the pipe wall. Additionally, in the present method it is possible to consider the influence of the thermal component to the complex stress state. The presented theoretical apparatus was confirmed with finiteelement modeling in Ansys Mechanical software environment. The results of the practical implementation of this work are given recommendations on assessing the technical condition of pipes with crack defects of different nature, as well as determination of the maximum allowable working pressure, which meets strength conditions on gas pipelines susceptible to stress corrosion cracking.

The article deals with the calculation of the characteristics of the thin-walled sleeve-type filter elements defined structural properties of the MR material. Existing results on the structural, filter, consumables and hydrodynamic characteristics of wire materials, the impact of their lifetime are fragmented and not linked to the calculation analytically closed form with the structural and technological parameters of the filter elements of the MR material. In the present paper we solve the problem of creating the calculation of the filter elements of the MR material with the specified filtering and hydrodynamic characteristics of the subject to the restrictions on the choice of dimensions and duration of use of the filter as a whole. The solutions of the fundamental problems to determine the structural and hydrodynamic characteristics of the MR material. The paper determines the possibility of creating a filter element, based on a given flow to ensure its performance and service life. We propose an algorithm for calculating the basic characteristics of the filter elements. It includes the solution of the system, and together with them the use of recommendations for selecting parameters of the structure and geometry of the MR material filter elements to ensure their desired filtering and hydrodynamic characteristics. This lets the rational parameters of the material structure with geometric MR material, filter and hydrodynamic characteristics of the filter elements. Such a generalized approach to the calculation of flow characteristics also provides an opportunity to take into account the life of the filter element. The use of the results is essential in the practice of creating high-performance filters based on thin-walled structures rational filter elements of bush type of woven wire MR material.

The article presents an analysis of the design work carried out in the design of liquid rocket engine (LRE) 11Д58MФ developed by JSC "RSC" Energy "for the upper stage (RB) ДМ. The developed liquid fuel rocket engine has a number of features that require innovative approaches to its design. The structure of the engine including experienced combustion chamber, the control system with functions for diagnostics and emergency protection, power supply of oxidizer and fuel tank with elements of devices that provide a guaranteed intake of propellants during his multiple inclusions, blocks thrusters operating on gaseous oxygen and providing impetus prelaunch booster and orientation in flight.The cooling chamber is performed without the use of liquid oxygen internal cooling is performed with a nozzle chamber with uncooled high expansion rationozzle. Workflow efficiency in the combustion chamber is provided by a slit mixing head, which uses the circuit components of mixed fuel: jet fuel into razing oxidant stream.Basic design and engineering solutions for combustion chamber: the use of a slit mixer-term head of the engine, performing geometry of cooling path with variable height, thickness and angle of the ribs to the axis of the chamber, the technology of manufacturing, assembly and soldering the mixing head and combustion chamber have been experimental testing. The LRE-linen design process was defined the composition ofpneumohydroautomaticequipment, small draft engines block, autonomous system universal and can be used in the development of similar engines.