Vol 19, No 4 (2020)

Full Issue

EDITORIAL
In Memory of Professor Victor Leonidovich Balakin
Lazarev Y.N.
VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):7-8
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My Friend Victor
Soifer V.A.
VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):9-13
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AIRCRAFT AND SPACE ROCKET ENGINEERING
Designing of minimum mass airframes under several loadings
Danilin A.I.
Abstract

We discuss the features of optimal force transfer in a thin-walled structure and use them to develop a method for defining the distribution of material over the structure elements for minimizing its volume. The suggested method works with one or several external loadings and allows one to determine the optimal structure and to recognize the phenomenon of Razani in which a structure with unequal stresses due to several loadings is more light-weight than a fully- stressed one. Using the developed method, we solved the original Razani problem and applied it for the optimization of the wing structure of a novel hypersonic airplane. It is shown that the determined material distribution is 8.78% lighter than that in a conventionally fully-stressed structure.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):14-29
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Development of improved performance electromagnetic valve for liquid rocket engine
Igolkin A.A., Chubenko T.A., Maksimov A.D.
Abstract

The problem of developing optimal-design electromagnetic valves is relevant for many industries. The development of technology is characterized by increased power and pressures used for actuator mechanisms, as well as by reducing the dimensions and mass of automatic units. The goal of this article is to develop an advanced electromagnetic valve that would ensure optimal combination of high performance, reliability, technological effectiveness and minimal cost. On the basis of standard dependences for electromagnetic phenomena a mathematic model of a SU.1 valve was developed. It was calculated in several special-purpose software packages: NISA, FEMM, ANSYS Maxwell. Parametric analysis was implemented in ANSYS Maxwell for variable working gap settings and values of current force in the solenoid. As a result, the magnetic induction distribution field was obtained. The results of modeling the operation of the electromagnetic valve and the magnetic induction distribution field are presented for variable working gap settings and different values of current force in the solenoid. The model of an advanced electromagnetic valve for a liquid rocket engine was developed on the basis of the dependences obtained. The duration of single engine firing obtained is 40 msec. The results obtained make it possible to create a valve with hold-open time of 800 msec, which is considered sufficient for application in electromagnetic direct current valves.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):30-42
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The effect of heat recovery on the optimal values of helicopter turboshaft engine parameters
Omar H.H., Kuz'michev V.S., Zagrebelnyi A.O., Grigoriev V.A.
Abstract

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):43-57
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Choice of mission trajectory plans and conceptual design of electrical propulsion module for launching payloads into circumterrestrial orbits
Salmin V.V., Kvetkin A.A., Russkikh A.S.
Abstract

The problem of increasing the efficiency of transport operations in space is currently coming to the fore. In the context of this problem, we investigated the possibility of developing a space transportation system including a chemical upper stage and an electric propulsion transport module capable of performing a specified range of space maneuvers. Electric propulsion module design was carried out for a given range of target orbits and payload mass with the provision of restrictions on the flight time. Calculation of the ballistic characteristics of the flight is performed and an optimal program of placing a low-thrust vehicle into orbit is defined. A procedure for defining the design parameters of a space transportation system and its conceptual design is proposed. The conceptual design of the space transportation system and the electric propulsion module were formed in the PTC Creo Parametric environment. On the basis of the results of the work, it can be concluded that it is possible to create a space transportation system with given parameters.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):58-69
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Investigation of the characteristics of the component of vibration of gas turbine engine gearbox that causes fatigue failures of its structural elements in case of tooth flank wear
Sundukov A.E.
Abstract

The paper presents an analysis of the component of vibration of the NK-12MP turboprop engine differential gearbox that is generated by the wear of the flanks of the teeth of the “sun gear – planet gear assembly” pair and at certain values of its intensity may cause fatigue breakdown of the engine’s structural elements. A complex of diagnostic indicators is determined on the basis of this component. Its intensity is shown to be maximal in steady-state operation of the engine with the greatest run time. The data obtained by the spectrum of maxima are shown to have higher information content as compared to the autospectrum data. The complex of diagnostic indicators proposed on the basis of the component under consideration makes it possible to successfully control the technical condition of the differential gearbox by the defects of “gear tooth flank wear”.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):70-79
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Determination of loads on perforated tank partition
Filipov A.G., Glazkov I.E.
Abstract

The article presents a solution to the problem of dynamic loading of a perforated partition located in the fuel tank of a launch vehicle. A technique for calculating the dynamic loading of the partition is described. Its equation of motion was decomposed into components and the loads at harmonic oscillations of the launch vehicle were calculated. The acceleration of the attachment points and the acceleration of the oscillators simulating the oscillations of the fuel tank, obtained from the solution of the general dynamic problem for assessing the hydrodynamic force for the launch vehicle, were given as the initial data for the dynamic calculation of loads. At this stage, the load on the partition was calculated, taking into account the added mass of the liquid in the event of an emergency shutdown of the propulsion system, as one of the most heavily loaded for the system under discussion. Non-linear dynamic analysis was used to calculate the loads on the perforated partition. As a result of the calculation, forces were obtained in the attachment points of the element in question.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):80-86
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MECHANICAL ENGINEERING
Pressing of porous bodies made of MR wire material
Ermakov A.I., Davydov D.P., Shchemelev V.I., Lazutkin G.V.
Abstract

The paper presents a solution to the problem of determining the basic equation for pressing of porous bodies made of MR material that  relates not only the molding pressure to the MR density, but also other physical parameters, including the technological parameters of blank formation. The paper outlines the basic assumptions of the theory of compression molding of items made of MR fibrous material. It has been proved that the ideal process of pressing porous bodies contains two stages for a range of relative densities [0,15; 0,7]. The basic equation of pressing of MR products was determined. It was proved that the equations of ideal pressing (in the absence of external friction forces) have the form of power-law dependences of the molding pressure on the density of the porous body. The power function of hardening of the wire material in the press was obtained. An experimental test of the hypotheses put forward and the assumptions made was carried out, which showed their validity. The obtained theory of axisymmetric pressing of fiber bodies and the obtained basic equation for pressing the MR material can be extended to various types of pressing modes and product shapes. The results of the performed theoretical and experimental studies, as well as their generalization, can serve as a basis for studying mass molding of porous bodies made of fiber materials, taking into account the uneven distribution of density over the volume.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):87-98
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Сalculation of characteristics of atomization of liquid supplied at an angle to the flow direction and justification of adjusting the angle of the nozzle inclination relative to the gas flow
Teslya D.N., Mityaev S.V., Drobyshev P.A.
Abstract

In the context of solving the problem of increasing the efficiency of aircraft with the capability to fly at supersonic speed, an important aspect is to reduce the amount of fuel consumed in this flight mode, since this is the most promising direction in the development of aviation and these modes are accompanied by a number of significant problems that require joint efforts of leading organizations in this field. To solve the problem of expanding the range of use of the afterburner during the flight of the aircraft and reducing the amount of fuel required for this flight, we suggest the angle of inclination of the fuel supply should be adjusted relative to the direction of gas flow. The results of calculating the distribution of the afterburner fuel over the volume of the afterburner, supported by known experimental data, are presented. The analysis of characteristic points on the graphs of the dependence of the main variables is carried out and possible reasons for the peculiar characteristics of the working process in the afterburner in the case of changing the nozzle mounting angle are indicated. Possible options of controlling the working process in the afterburner are suggested.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):99-107
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Technique for assessing the probability of survival of structural members with delaminations
Chernyakin S.A.
Abstract

The paper presents a technique of quantitative assessment of probability of failure-free operation of composite structures containing an ensemble of defects in the form of delamination. This method is based on approaches of general reliability theory. The proposed method was validated relative to the assessment of reliability of a composite conical bay with multiple delaminations generated under loads at the stage of inserting the launch vehicle into orbit. The statistical dynamic problem was solved by using Monte Carlo method which was implemented by means of algorithms developed by the author in ANSYS software. Nonlinear analysis of the conical bay buckling was carried out for each implementation. Quantitative assessment of survival probability was conducted on the basis of the hypothesis of the law of Gaussian distribution of load-bearing capacity and using the graphical method of reliability calculation. Good agreement of the results obtained by both methods was noted.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2020;19(4):108-118
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