Vol 23, No 1 (2024)

Full Issue

AIRCRAFT AND SPACE ROCKET ENGINEERING

Mathematical model of a generalized quadcopter kinematic scheme and its software implementation

Zelenskiy V.A., Kovalev M.A., Ovakimyan D.N., Kirillov V.S.

Abstract

A generalized kinematic scheme of the installation of quadcopter motors is presented and its main advantages are described. In accordance with the scheme, a mathematical model of the kinematics of the quadcopter was developed. The model was implemented in the MatLab software environment. The presented mathematical expressions are used to calculate kinematic characteristics, such as the values of the thrust of the motors and the reverse effect of the motors on the body of the quadcopter. The comparison of the obtained data with the experimental characteristics showed a 5% deviation of the magnitude of the dependence of the thrust on the average value of the voltage on the motors and a 30% deviation of the magnitude of the dependence of the motor action on the thrust magnitude.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):7-20
pages 7-20 views

Ballistic analysis of a mission to Jupiter’s moon Callisto with landing on the surface

Kovalev V.V., Marchenko A.D., Starostina T.V., Sharipova A.R.

Abstract

The article presents the results of a study on the basis of which a set of mathematical models was developed for ballistic analysis of a mission to send a small spacecraft to the satellite of Jupiter, Callisto and its landing on the surface of the satellite. In this mission, it is proposed to use a gravity assist maneuver around the Earth and an aerodynamic maneuver near Jupiter to reduce the cost of the working fluid of the spacecraft. The minimum required thrust of the engines and the duration of the soft landing maneuver of a spacecraft with a given mass on the satellite are estimated. The optimal launch date was found for the possibility of launching a spacecraft using a medium-lift Soyuz-2 launch vehicle. The simulation of the movement was carried out numerically, in the Mathcad mathematical package, all the dependence diagrams necessary for the analysis of the movement were constructed.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):21-37
pages 21-37 views

Reducing energy consumption of vertical take-off and landing unmanned aerial vehicle using hybrid technical solutions

Lukyanov O.E., Hoang V.H., Komarov V.A., Nazarov D.V., Kurkin E.I., Quijada Pioquinto J.G., Chertykovtseva V.O.

Abstract

The paper describes possibilities of increasing the energy efficiency and reducing the takeoff weight of unmanned medium-heavy vertical takeoff and landing aerial vehicles of the airplane type. The authors propose a new hybrid type of unmanned aerial vehicle with a hybrid propulsion system, its aerodynamic design, method of realization of vertical takeoff/landing and cruising mode of flight which make it possible to reduce the takeoff weight of the aircraft, the weight of the basic propulsion system and the mass growth factor in comparison with the existing unmanned aerial vehicle of similar class, made according to the previously known technical solutions. The authors propose a methodology for optimizing the parameters of the configuration of the unmanned aerial vehicle considering the peculiarities of the implementation of vertical takeoff. The paper presents calculations of characteristics of vertical takeoff and landing unmanned aerial vehicles of existing types and the new hybrid type. The authors give quantitative estimates of improving unmanned aerial vehicle characteristics due to the new proposed technical solutions.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):38-54
pages 38-54 views

Analysis and improvement of characteristics of power supply systems for the small space vehicle of the AIST-2 type

Mordanov M.R., Safronov S.L.

Abstract

The power supply system being created is intended to provide electricity to spacecraft systems. It ensures that the design characteristics of the solar battery of the prototype are preserved and makes it possible to install means to support the thermal conditions of the photovoltaic battery while maintaining the cost of production of the prototype solar battery. Various types of solar energy concentrators are considered: concentrators in the form of individual convex linear Fresnel lenses, Flexible Array Concentrator Technology concentrators, Stretched Lens Array concentrators. A method for improving the characteristics of the spacecraft solar system is presented. The methodology includes the calculation of various types of concentrators, types of photovoltaic converters and types of solar battery frames. As an example of the implementation of the methodology, the design of solar battery panels was developed. A comparative table of the solar battery before and after modernization is provided.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):55-66
pages 55-66 views

Main approaches and features of the design of aircraft hydro-mechanical control systems

Petrov P.V., Tselischev V.A., Kuderko D.A.

Abstract

The main purpose of the article is to identify the main approaches and define the concept when modeling the hydro-mechanical control systems of an aircraft. The advantages and importance of a computational experiment with the aid of a virtual test bed at the stage of constructive parametric debugging of the elements of complex hydraulic systems are emphasized. The characteristics obtained from the results of the computational experiment will allow us to determine the level of adequacy of the models and subsequently choose the most optimal design and operational parameters.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):67-79
pages 67-79 views

Optimization of trajectory motion of the first stage of an aerospace system

Khramov A.A.

Abstract

The problems of optimizing the trajectory motion of the first stage of an aerospace system according to the criterion of the maximum of the final mass are considered. The control is the angle of attack and thrust of the engines. Control optimization is carried out on the trajectory section from the point of bringing the first stage to the launch area until the motion parameters required for separation of the space stage are reached. The Pontryagin’s maximum principle is used to determine optimal control programs. The solution of the problem without restrictions on the modes of motion is carried out using the example of acceleration and climb of the first stage of the RASCAL aerospace system. A method is proposed for determining approximate optimal control in a problem with a limitation on the altitude range of the engines with separate optimization of the active and passive sections and the search for the optimal point of their coupling. Changes in control program, trajectory, and fuel consumption are discussed when limiting the maximum flight altitude in the active section.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):80-92
pages 80-92 views

Verification of aero-engine numerical rotor models based on virtual static structural and modal tests

Shaposhnikov K.V., Degtyarev S.A., Leontiev M.K., Anisimov S.V.

Abstract

A method for developing a numerical rotor model and its further verification based on the results of virtual static structural and modal tests was proposed. Approbation of the method was performed on a model of a low pressure rotor of a high-bypass turbofan engine constructed in a software system for rotor dynamics simulation DYNAMICS R4. Refined on the basis of the results of virtual static structural tests, the model of the rotor main force action line showed good agreement in frequencies and mode shapes with the results of a finite element model, obtained during a virtual modal test.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):93-108
pages 93-108 views

MECHANICAL ENGINEERING

Neural network controller of a gas turbine plant low emission combustor

Avgustinovich V.G., Kuznetsova T.A., Sukharev A.A.

Abstract

One of the most important gas turbine engine components is the combustion chamber, the main source of harmful emissions. The study is devoted to the central issues of designing and testing of an automatic control system of harmful emissions and pressure pulsations in flame tubes of a gas turbine plant with a capacity of 16 MW GTP-16 based on a PI-controller with a built-in neural network mathematical model of a low-emission combustor (LEС). Algorithms for a neural network controller of emission of nitrogen oxides and carbon monoxide into the atmosphere, as well as pressure pulsations in the LEC’s flame tubes were developed. The algorithms are given in a graphical programming environment and integrated into the automatic control system of GTP-16, implemented on the PXI NI hardware and software platform. The performance of the emission controller was checked during bench tests on the GTP-16 simulator with LEС neural network model serving as a virtual emission sensor. The errors in estimating the emission of nitrogen and carbon oxides and pressure pulsations in the flame tubes were determined. The normality of the error distribution of the developed nitrogen oxide emission model was proven. A conclusion about the prospects of using neural networks for the development of an adaptive control system of emissions and flame tube pressure pulsations for LECs of the gas turbine plants was drawn.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):109-122
pages 109-122 views

Determination of completeness of combustion, temperature and emission characteristics in a swirl flow based on the theory of turbulent combustion

Aleksandrov Y.B., Mingazov B.G.

Abstract

A study of combustion characteristics in a swirling jet was carried out from the perspective of the theory of turbulent combustion. Particular attention is paid to the reverse-flow area formed from the vane swirler. Based on the known composition of the mixture, the parameters of the speed of propagation of the flame front, completeness of combustion, temperature and emission of nitrogen oxides are successively determined. The created analytical technique was tested in the combustion range of inhomogeneous and homogeneous mixtures. Calculations showed the dependence of emission on the mixing parameters.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):123-136
pages 123-136 views

Effect of HF and ER additions on the mechanical properties and microstructure of AL-MG-SC-ZR system alloys

Aryshenskii E.V., Aryshenskii V.Y., Ragazin A.A., Rasposienko D.Y., Grechnikov F.V., Makarov V.V., Konovalov S.V.

Abstract

The study addresses the effect of 1580 and 1590 alloys cold rolled strip annealing practices on the alloys’ grain structure and mechanical properties. The 1590 alloy differs from the 1580 alloy by hafnium and erbium additions. Samples of such alloys were produced by casting into a steel mold. After that they were homogenized during 4 h at 440°С. Then the samples were hot rolled at 440°С, with further cold rolling to 2 mm, with the cumulative percentage reduction equal to 66%. The cold rolled strip was annealed at the temperature ranging from 330 to 440°С with 1 h soaking. The sizes and morphology of Al3Sc strengthening nanoparticles were examined in homogenized condition using transmission microscopy. The mechanical properties and grain structure were defined in cold rolled and annealed conditions. During homogenizing annealing in the 1590 alloy finer strengthening nanoparticles are formed compared to the 1580 alloy. Such features of the microstructure can be explained by the presence of erbium, promoting formation of additional Al3Sc-type nanoparticles nuclei, and hafnium, preventing their further growth. Non-recrystallized structure was identified in both alloys after cold rolling and final annealing. The 1590 alloy has better mechanical properties, regardless of the annealing temperature, which is explained by a larger portion and smaller size of strengthening nanoparticles.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):137-146
pages 137-146 views

New high-strength aluminum alloy on the basis of secondary materials

Barykin M.A., Naumova E.A., Belov N.A., Finogeev A.S., Koshmin A.N.

Abstract

Six alloys of the Al-Ca-Zn-Mg system with additives of copper, manganese, iron and silicon were studied in order to simulate the composition of an alloy prepared on the basis of secondary aluminum. The alloys were made in the form of ingots with dimensions of 140×200×20 mm that were subjected to subsequent deformation treatment by hot rolling from a thickness of 20 mm to a thickness of 1 mm, and then cold-rolled sheets with a thickness of 0.5 mm were obtained from them. A cylindrical ingot with a diameter of 40 mm and a length of 200 mm was also made. Rods with a diameter of 14 mm were obtained from it by radial displacement rolling. Hot deformation treatment of ingots was carried out at a temperature of 450°C without prior homogenizing annealing. Cast and deformed specimens were examined using optical and scanning electron microscopy. No coarse acicular particles of iron- and silicon-containing phases, as well as any other coarse intermetallides, were found in the microstructure of the specimens. Mechanical tests were carried out using the method of uniaxial tension of deformed semi-finished products that were not subjected to additional strengthening heat treatment. According to the test results, an alloy of optimal composition was selected. The possibility of obtaining products from high-strength and high-tech aluminum-calcium alloy based on secondary raw materials without the use of homogenization and quenching was established.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):147-159
pages 147-159 views

Investigation of the influence of broadband mechanical disturbances on the quality of recording interference patterns of GTE-wheel oscillations using a digital speckle pattern interferometer

Ivchenko A.V., Safin A.I.

Abstract

The effect of broadband disturbances on the operation of a noise-immune digital speckle pattern interferometer with a continuous wave laser emitter and a diffuse-scattering element arranged in front of an oscillating turbine wheel has been studied. Visibility dependences of the recorded interference patterns were obtained under the action of different types of artificially created disturbances. It is shown that the most dangerous mechanical disturbances for the operation of a speckle pattern interferometer are periodic noise and pink noise, whereas white noise and natural vibrations of the floor in the room where the experimental setup was accommodated do not significantly influence the quality of the information recorded by the interferometer. This article analyzes the influence of the mechanical properties of the diffuse-scattering element arranged in the speckle pattern interferometer on the quality of the obtained interference patterns. A relationship between the growth of forced tangential oscillations of the diffuse-scattering element and a decrease in the contrast of interference fringes was noted. In this case, an increase in the thickness of the organic glass plate of the diffuse-scattering element up to 8 mm leads to the neutralization of the pink noise action on the speckle pattern interferometer operation. At the same time, the effect of periodic noises decreases the contrast of interference patterns recorded for the cases of using 5 mm and 8 mm thick organic glass plates.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):160-176
pages 160-176 views

Development of a mathematical model of the internal structure of a granular heat accumulator for launching a mono-fuel gas generator

Zrelov V.A., Lykin A.Y.

Abstract

The issue of improving energy-mass characteristics is one of the most important ones in the development of gas generators for various purposes. In this regard, as part of the search for ways to use promising types of fuels, experimental studies of gas generators operating on composite mono-fuel based on nitrate esters were carried out. As a device initiating the combustion reaction, a granular self-heating heat accumulator was used, which was placed in a cylindrical combustion chamber. Experimental studies made it possible to reveal the features of a complex and multi-stage process of mono-fuel conversion occurring in the pore space of the gas generator combustion chamber on the surfaces of the granules and inside a complex system of channels consisting of elementary cells formed by these granules. In this case, the pore space of the heat accumulator is granular filling of mono-dispersed granules of a disordered structure. The task of the work described in the article was to create a mathematical description of granular filling of a disordered structure, solved in a two-dimensional formulation. The article proposes a method of transition from hexagonal stacking to conditionally ordered one that combines the compactness of hexagonal stacking and the ease of description of cubic stacking. The resulting stacking makes it possible to represent half of the frontal section of the granular heat accumulator in the form of a vertical flat layer with a given structure determined by porosity, granule diameter and dimensions of the combustion chamber – its length and diameter. The proposed approach for the transition from a disordered filling structure to a conditionally ordered structure made it possible to develop a mathematical model that describes the internal structure of the launch heat accumulator and determine the coordinates of the heat accumulator zones in which various stages of monopropellant conversion take place. This will allow us to proceed to the formation of a description of the working process of gas generators with a granular self-heating heat launch accumulator.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):177-187
pages 177-187 views

Effective volume of short carbon fibers in a composite from chopped thin tapes

Komarov V.A., Abdullayev R.F.

Abstract

This paper discusses a composite material from chopped thin narrow polymer tapes reinforced with carbon fibers and a polymer binder. The problem is posed to analytically determine the elastic and strength characteristics of the composite with a known minimum set of basic characteristics of the components. A methodology for sequential solving of the problem at the micro- and meso-levels is proposed. The key point in the methodology is the introduction of the “effective fiber volume factor” in the short filament and the way to calculate it using the “load-carrying factor” criterion. The following are presented: the results of calculating  Young’s modulus and tensile strength of material samples from parts of tapes with fixed lengths (6, 12, 18 and 24 mm); comparison with the experimental data and evaluation of accuracy and limits of the applicability of this methodology.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):188-202
pages 188-202 views

Investigation of surface morphology, optical and electronic properties of Mg2Si thin films on Si(111)

Fomin D.V., Polyakov A.V., Galkin K.N., Galkin N.G.

Abstract

The article presents the results of a study of the elemental composition, surface morphology, optical and electronic properties of Mg2Si thin films formed on Si (111). Both samples containing films were formed in layers by the method of reactive epitaxy, but at different heating temperatures of the substrates. The formed films consisting of alternating layers of Mg and Si at a ratio of 3:1, according to electron Auger spectroscopy, contain Mg and Si atoms in the associated layers. The Raman light scattering method established the presence of peaks on the graphs of samples at a shift of 258 and 348 cm-1 belonging to Mg2Si. Infrared spectroscopy data also indicate the presence of magnesium silicide in the films. The thickness of Mg2Si films was estimated from the data of the known dependence of the amplitude of absorption peaks at 272 cm-1 on the absorption coefficient, which gave the values of the thicknesses of the grown films. Based on the results of the study of samples in the infrared-ultraviolet range and on the basis of geometric calculations, the width of the Mg2Si band gap was determined.

VESTNIK of Samara University. Aerospace and Mechanical Engineering. 2024;23(1):203-215
pages 203-215 views

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