Vol 20, No 4 (2019)

Aviation and rocket and space technology

On the motion of bodies based on changes in the kinetic moment

Razoumny Y.N., Kupreev S.A.


The controlled motion of a body in a central gravitational field without mass flow is considered. The possibility of moving the body in the radial direction from the center of attraction due to changes in the kinetic moment relative to the center of mass of the body is shown. A scheme for moving the body using a system of flywheels located in the same plane in near-circular orbits with different heights is proposed. The use of the spin of elementary particles is considered as flywheels. It is proved that using the spin of elementary particles with a Compton wavelength exceeding the distance to the attracting center is energetically more profitable than using the momentum of these particles to move the body. The calculation of motion using hypothetical particles (gravitons) is presented. A hypothesis has been put forward about the radiation of bodies during accelerated motion, which finds indirect confirmation in stellar dynamics and in an experiment with the fall of two bodies in a vacuum. The results can be used in experiments to search for elementary particles with low energy, explain cosmic phenomena and to develop transport objects on new physical principles.

RUDN Journal of Engineering Research. 2019;20(4):267-275
pages 267-275 views

Design of the structural arrangement for a space reflector via parametric and topology optimization

Filina E.K., Golubev E.S., Mikhailovskiy K.V., Arkhipov M.Y.


Development of the optimal structural arrangement for a reflector with the aim to improve its mass and design is of importance due to the necessity to increase areal density and decrease rigidity of the modern space antennas vehicles. Currently, CAE-systems allow to design reflectors using both traditional methods, for example, parametric optimization, and methods which are innovative in this field, such as topology optimization. The paper compares two methods of the structural arrangement design for a thin dimensionally stable reflector operating as part of a geostationary spacecraft: parametric and topology optimization. The algorithms of the structural arrangement development which include the statement of the optimization problem, geometry design and a number of check analyses are presented. A number of structural of a space reflector design under the action of loads at the stage of launch, temperature gradients at the exploitation conditions and modal analysis is performed. The designed reflectors are compared. The studies performed allowed us to develop the optimal structural arrangement for a space reflector using the parametric and topology optimization. The optimal structural arrangement for a space reflector using the optimization could be produced surface figure error (estimated in RMS) with respect to the theoretical paraboloid.

RUDN Journal of Engineering Research. 2019;20(4):276-284
pages 276-284 views

Earth science

Diagnosis, recommendations and optimization for potable water treatment plant in Cauca (Colombia)

Melendez Giraldo D.S.


Currently the water supply system in the municipality of Corinto (Cauca) in Colombia provides drinking water to the entire urban and rural population of the municipality. In order to provide drinking water to the entire population, it became necessary to optimize and/or expand the existing water treatment plant. The article presents an assessment of the consideration of two optimization options: the need for reconstruction of existing water treatment facilities or the construction of additional water treatment units. A reasonable proposal was made to expand the station by building additional water treatment units, including advanced modern water treatment technologies, such as coagulation, flocculation, sedimentation, filtration, sorption, settling using thin-layer modules and disinfection, based on the survey (diagnostics), technical and economic analysis, analysis of the efficiency of the existing water treatment plant, taking into account the quality of drinking water preparation, confirmed by the analysis of samples, the results of physical, chemical and microbiological tests, indicating the optimal quality of drinking water for human consumption. The use of modern water treatment technologies will allow to achieve the required quality of purified sufficient water for drinking purpose.
RUDN Journal of Engineering Research. 2019;20(4):302-307
pages 302-307 views

Definition of acceptable parameters of defects in basic details of forging and press machines

Kornilova A.V., Zaya K.


In the Soviet Union, a unique worldwide industry was created for the serial production of forging equipment. Currently, even these machines that have served their design life are in working or maintainable condition. This has led to the fact that there is now a large market for the secondary sale of such machines, including in the countries of Southeast Asia and India. However, with the secondary sale of such equipment, some inevitable damage builds up in the basic parts. In addition, the first copies of such models, put up for secondary sale, were produced at a time when non-destructive testing methods were not developed. Some defects could be undetected. When buying a machine dismantle, transport, install and test. Cases were recorded when defects were strained during installation and testing in the base parts, which made it difficult or impossible to use such equipment. Sometimes this type of equipment (during modernization) is used to carry out technological operations that require more power than previously declared. Therefore, when buying/selling (or upgrading), it is necessary to draw up cards of permissible defects, which, when superimposed on the cards of the detected defects, will allow to reject/determine the remaining life/limit the technological strength of the crank machine so that defects during further operation are not affectted and do not lead to emergency situation. The methodology for determining the permissible parameters of subsurface elliptical cracks is shown on the example of a press bed KD2130 (BZMP).

RUDN Journal of Engineering Research. 2019;20(4):308-315
pages 308-315 views

Mechanical engineering and machine science

An experimental study of the stress-strain state of the engine piston skirt on the engineless stand

Smirnov S.V., Kopylov V.V., Makarov A.R., Vorobyev A.A., Shkarin K.V.


The article describes the features developed by the authors of the profiling method of the piston skirt, provides the main parameters that affect the lubrication conditions of the piston skirt and the magnitude of mechanical losses. In computational studies, the basic formulas are given for determining the thickness of the oil layer in a piston skirt - cylinder sleeve conjunction to assess the nature of friction. To determine the deformations, the finite element method is used on the spatial model of the piston. To verify the finite element model, a stand for experimental studies was developed. The article describes the developed stand, the methodology and results of experimental studies of the stress-strain state of the two-piece piston skirt obtained at this stand and a comparative analysis of the results of the calculated and experimental studies of the stress-strain state of the two-piece piston skirt of a diesel engine. The research results showed that the developed stand can be used to verify mathematical models for calculating the stress-strain state of the piston skirt in the pilot production of internal combustion engine pistons to accelerate and reduce the cost of the piston design development process, as well as the results of experimental studies obtained at the stand, can be used as initial data for the developed mathematical model of the dynamics of the movement of the piston and the profiling of the piston skirt.

RUDN Journal of Engineering Research. 2019;20(4):285-292
pages 285-292 views

Comparative analysis of software for the study of statistical methods of control of product quality

Kozhanov R.V., Kozhanova E.R., Sorokina L.A.


The article discusses the comparative analysis of software (MS Excel, Mathcad and Matlab) for the study of statistical methods of product quality control necessary for the training of future specialists in the field of product quality. The choice is determined by the presence of this software in the educational institution. Statistical methods of product quality control are mandatory elements of modern quality management systems implemented at Russian enterprises, the competitiveness of which largely depends on the ability of the company's personnel to apply these methods in practice at all stages of the product life cycle. The analysis of product quality begins with the construction of a histogram to identify avoidable and irremediable defects and compare it with the normal distribution curve. The process of forming the shape of the normal distribution curve can be traced in the construction of control maps based on a scatter plot of the sample. The next step is the construction of dot diagrams, on the basis of which control maps are built (in our case - the control map of Shewhart). The final step in training is the construction of Pareto diagrams to identify the causes of defects with ABC analysis. The authors conducted a comparative analysis of software products MS Excel, Mathcad and Matlab for the implementation of basic statistical methods of product quality control. For training it is proposed to choose MS Excel because of the availability of the Data Analysis package, free analogues that are widely used in enterprises, the ability to store the original data and use them in other programs (data import).

RUDN Journal of Engineering Research. 2019;20(4):293-301
pages 293-301 views

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