Vol. 7, no. 4, 2023
OMSK SCIENTIFIC BULLETIN. SERIES «AVIATION-ROCKET AND POWER ENGINEERING»
CONTENTS
POWER AND CHEMICAL ENGINEERING
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A. G. Nikiforov, L. A. Muslova. The effect of wall mobility on mass flow in a slow-moving long-stroke stage DOI: 10.25206/2588-0373-2023-7-4-9-14 In modern models and calculation methods of existing high-speed reciprocating compressors, the mobility of the walls is not considered due to the insignificant value and insignificant effect on the efficiency of the working process. Low – speed piston machines currently being developed at OmSTU have a number of features – first of all, an elongated cylinder, subject to large deformations compared to existing analogues and a long compression time. Which naturally significantly affects the flow of the workflow. The conducted studies have shown that not considering the mobility of the walls can lead to significant errors obtained when modeling the working process of low-speed reciprocating compressors. Keywords: reciprocating compressor, mass leaks, mathematical modeling, operating mode. |
9-14 |
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V. A. Pronin, A. V. Kovanov, V. A. Tsvetkov, E. N. Mikhailova, P. A. Belov. Assessment of the influence of gap wall mobility factor at calculation of leakage in working section of a scroll compressor. Part 2 DOI: 10.25206/2588-0373-2023-7-4-15-24 Leakage of the working substance in the compressor's flow gaps accounts for a large share of its volumetric losses. The optimality of calculated and approximated characteristics depends on the accuracy of quantitative component determination. Accordingly, an adequate and qualitative mathematical model should include the factor of non-stationarity of the leakage process, taking into account the mobility of scroll elements. At the same time, the real properties of the working medium, characterized by the compressibility coefficient, play an important role in the nature of leakage. Thus, in this article the task of creating a mathematical model adequate to the actual process of compression and allowing to estimate the degree of influence of the slit walls mobility on the leakage through them is set. The result of numerical calculations has a smaller error in relation to experimental data, and it also showed a significant influence on the leakage rate of both the pressure difference at the edges of the slot and the viscosity properties of the vapour-oil mixture, a significant percentage of which is oil. Keywords: scroll compressor, unsteady flow in slots, working gap, mobility of slot walls, leakage calculation methodology. |
15–24 |
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V. L. Yusha, M. A. Sutyaginskiy, A. Yu. Gromov, P. V. Ushakov, Yu. A. Potapov On the relationship of digital technological platforms of large chemical and oil refining industries with the technical appearance of the compressor equipment fleet DOI: 10.25206/2588-0373-2023-7-4-25-32 Issues related to possible problems in the implementation of digitalization programs for large enterprises for the processing of natural hydrocarbon and mineral raw materials, due to the discrepancy between the technical level of the existing fleet of compressor equipment of these enterprises, both with the requirements of modern production and modern achievements in the field of compressor engineering, are considered. It is noted that the discrepancy between virtual and physical technological objects leads to an overestimation of the costs of creating and maintaining IT products, as well as to a decrease in their efficiency. The ways of improving the element base of compressor equipment are proposed. A theoretical analysis of the functioning of an alternative design of a rotary vane compressor with water supply to its flow part is performed. Its example shows that there are obvious prerequisites for replacing the fleet of existing reciprocating process compressors with more advanced designs, the production of which can be completely based on domestic technologies and localized in the Russian Federation in the interests of the core industries of the processing industry. Keywords: digitalization, reliability, operational characteristics, reciprocating compressors, water injection rotary vane compressors, mathematical model. |
25–32 |
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E. V. Dubinin, B. F. Idiyatullin, N. G. Khasanov Optimization of centrifugal compressor stages DOI: 10.25206/2588-0373-2023-7-4-33-39 The article describes а hydraulic efficiency increase in the centrifugal compressor stage using automatic optimization algorithms. The optimization criterion is the polytropic efficiency of the intermediate compressor stage. The sequence of stages of the optimization process in the Fine/Design3D software module of the Numeca software package is presented. The creating process a solid model of the compression stage is shown. The perfomance curves of the developed stage after optimization of the shape of the rotor and stator elements are also presented. Keywords: flow pass, centrifugal compressor, energy efficiency, performance curves, CFD, Numeca, optimization. |
33–39 |
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D. V. Mylkin, A. V. Volkov, B. M. Orakhelashvili, A. A. Druzhinin, V. Yu. Lyapin Method for assessing the theoretical characteristics of small axial hydraulic turbines DOI: 10.25206/2588-0373-2023-7-4-40-47 Energy supply to remote areas remains a technical and social challenge. Construction of transmission lines to provide electricity to such areas is expensive and not always possible. One of the promising areas in this area is local energy generation based on local resources, in particular small watercourses, using small hydroelectric power plants (SHPPs). SHPPs are small hydropower facilities that use the energy of small watercourses to generate electricity. They have a number of advantages over traditional energy sources, such as environmental friendliness, low operating costs and high efficiency. However, the widespread introduction of small hydroelectric power plants is hampered by the lack of mass production of small hydraulic turbines and difficulties in designing low-power plants. Designing hydraulic turbines is a complex task that requires solving the inverse problem of hydrodynamics and finding the optimal shape of the flow path. To simplify the design of hydraulic turbines in the modern world, specialized software is used using various methods, including flow analysis, energy loss and blade shape optimization. This article based on an analysis of existing methods for designing and using a mathematical model of a hydraulic turbine with simplified blades, proposes a method for designing and analyzing the theoretical characteristics of the resulting hydraulic turbine. In conclusion, taking into account the use of the methodology for designing a hydraulic turbine for given parameters, its assessment is given, as well as ways to possibly improve the accuracy of the results obtained. Possible areas of application of the outlined design methodology are indicated. Keywords: microhydroturbine, blade skeleton, hydraulic turbine impeller, design and optimization of microhydroelectric power station. |
40–47 |
AVIATION AND ROCKET-SPACE ENGINEERING
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V. N. Blinov, V. V. Kositsyn, A. I. Lukyanchik, P. V. Stepen, P. S. Yachmenev Autonomous experimental studies resistojet with two autonomous heating elements for nanosatellites DOI: 10.25206/2588-0373-2023-7-4-48-55 The purpose of the work is to conduct autonomous experimental studies of an resistojet with two autonomous heating elements with a diameter of 4 mm. As a result of experimental studies of the resistojet, the heating dynamics of the micromotor structure and the working fluid (isobutane) in the power range from 5 W to 60 W was determined. Experimental studies have shown the possibility of using the proposed resistojet design with two autonomous heating elements not only on small spacecraft, but also on micro- and nanosatellites under conditions of limited on-board energy. Keywords: nanosatellite, propulsion system, resistojet, autonomous experimental research, autonomous heating element. |
48-55 |
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V. I. Ruban, V. N. Blinov, V. V. Kositsyn, A. I. Lukyanchik, P. S. Yachmenev, P. V. Stepen. Constructing the trajectory of a small spacecraft for flying around the base spacecraft for the purpose of external inspection and estimating the energy costs for the flyby maneuver DOI: 10.25206/2588-0373-2023-7-4-56-64 The paper presents a methodology for constructing a flyby trajectory of a base spacecraft for the purpose of inspecting it using a small spacecraft carried on board and estimating the required characteristic velocity reserves for the flyby maneuver. The use of approximate calculation methods made it possible to obtain the simplest dependences of trajectory parameters with high accuracy. The technique allows not only to estimate the energy costs for orbital maneuvers, but also allows one to calculate the values of control impulses for the real problem of controlling the movement of a small spacecraft relative to the base spacecraft. Keywords: small spacecraft, basic spacecraft, flyby trajectory, orbit, flyby maneuver. |
56-64 |
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E. P. Zlobin, A. I. Khaimovich, A. V. Balyakin Investigation of the process of vibration processing of AlSi10Mg aluminum alloy samples obtained by SLS technology DOI: 10.25206/2588-0373-2023-7-4-65-71 The results of the experiment aimed at studying the effect of vibration treatment on samples of various sizes made of AlSi10Mg alloy obtained by selective laser melting are presented. During the investigation, changes in the roughness and rounding of sharp edges were monitored depending on the size of the samples and the angle of inclination of the wall. Also, the formation of low contact zones and untreated zones during processing was studied. As a result of the experiment, a minimum surface roughness of Ra 1.2 microns was achieved. The length of the untreated zones, depending on the geometry, ranged from 0.5 mm to 6 mm. Rounding occurred most effectively in the first 4 hours of processing on the edges formed by an obtuse angle. The results obtained allow us to better understand the features of vibration processing of aluminum alloy products and optimize the process to achieve the required surface characteristics. Thus, the results of the study can be useful for various industrial sectors where aluminum alloys are used, and contribute to the further development of processing technologies for products obtained using SLM technology. Keywords: post-processing, selective laser melting, barrel finishing, vibration treatment, surface layer. |
65-71 |
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M. V. Smagin, E. E. Kolyagin, I. S. Vavilov The analysis of operability of dilatometric microthruster with polymer working components DOI: 10.25206/2588-0373-2023-7-4-72-78 The article describes the device of a dilatometric microthruster. The study of the device's operability with low power consumption was carried out. It was based on the designed prototype of the thruster in vacuum conditions. The results of the experiments showed that at the pressure of the working gas-air mixture at the thruster inlet of 1 atm. and with a mass flow rate of gas 2,33•10–7 kg/s, the device was able to produce a thrust value within 33 mkH, with a specific thrust pulse of 140 m/s. In turn, the power consumption of the device was only 0,81 W. Keywords: microthruster, dilatometric microthruster, cold gas, energy efficiency, thrust, specific thrust impulse. |
72-78 |
MATERIAL SCIENCE AND PROCESSING TECHNOLOGY
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D. A. Negrov, V. Yu. Putintsev, A. I. Glotov, D. A. Veber The effect of ultrasonic vibrations with superimposed low-frequency modulation on the mechanical, tribological properties and structure of a multicomponent polymer composite DOI: 10.25206/2588-0373-2023-7-4-79-84 One of the tasks of polymer materials science is to study the possibilities of improving the complex of elastic-strength characteristics and tribological properties of polymer composite materials by improving the manufacturing technology. In this paper, the influence of ultrasonic vibrations with a frequency of 17 kHz with a low-frequency vibration with a frequency of 100 Hz during synthesis on the properties and structure of a multicomponent polymer composite material of the КВН-3 trademark is considered. The result of the research, it was found that the influence of the technological mode of pressing, consisting in the combined effect of ultrasonic vibrations with frequency and low-frequency vibration during the synthesis of КВН-3, makes it possible to increase the complex of elastic-mechanical characteristics: tensile strength by 3 %, elongation by 6 %, modulus of elasticity by 10 %, hardness by 2 %, compared to the industrial manufacturing method, as well as to reduce the intensity of mass wear by 68 % and the coefficient of friction by 3 %. The structure of polymer composite materials after different technological pressing modes was examined. The fibrillar structure of the polymer matrix after the technological regime with the influence of ultrasonic vibrations and low-frequency modulation becomes finer and more uniform. Keywords: polytetrafluoroethylene, ultrasonic exposure, low-frequency modulation, polymer composite materials, wear resistance. |
79-84 |