Vol. 6, no. 2, 2022
OMSK SCIENTIFIC BULLETIN. SERIES «AVIATION-ROCKET AND POWER ENGINEERING»
CONTENTS
POWER AND CHEMICAL ENGINEERING
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Yu. B. Galerkin, A. F. Rekstin, V. B. Semenovskiy, L. N. Marenina, O. A. Solovyeva, A. A. Drozdov, L. N. Rozanov, P. N. Brodnev Centrifugal compressors of turboexpander units: development of approaches and experience of optimal design DOI: 10.25206/2588-0373-2022-6-2-9-20 The process of designing a new turboexpander unit using the Universal modeling method consists of several stages: preliminary design, optimization, calculation of gas dynamic characteristics. The development of modern computational methods and the accumulation of experimental research results has allowed to improve mathematical models in the field of calculation and design of CC turbo-expander units. The resulting model includes 22 empirical coefficients, the calculation error is 1,8 %, which is sufficient for its practical application in project activities. Keywords: centrifugal compressor, turboexpander unit, loading factor coefficient, mass flow coefficient, efficiency, mathematical model. |
19-20 |
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S. S. Busarov, A. V. Nedovenchany, K. A. Bakulin, N. G. Sinitsin, A. A. Panyutich Experimental evaluation of the influence of crankshaft rotation frequency on the amplitude of pressure pulsations in gas communications of low-flow reciprocating compressors DOI: 10.25206/2588-0373-2022-6-2-21-26 The presence of gas pressure pulsations in the suction and discharge pipes of reciprocating compressors is associated with their periodic connection and disconnection from the working chamber during the operation of self-acting valves. The present work is devoted to the development of a methodology for experimental investigation of pressure pulsations in gas communications of reciprocating compressors under various operating modes in relation to an existing laboratory installation and comparison of the results obtained with the results of calculations obtained on the basis of the use of well-known repeatedly tested techniques.This proven technique can be used to study pressure pulsations in gas communications of a wide class of low-flow reciprocating compressors. Keywords: piston stage, experimental studies, pressure pulsations, suction line, discharge line. |
25–26 |
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A. D. Vanyashov Correction of procedure for conversion of gas-dynamic characteristics of high-pressure centrifugal сompressor stage in case of frequency change rotor rotation DOI: 10.25206/2588-0373-2022-6-2-27-35 The proposed corrected method of conversion of gas-dynamic characteristics of high-pressure stage of turbocharger operating in the area of high circumferential speeds (conditional Mach numbers > 0,5) to other rotor speeds is given in the work, taking into account deviation from kinematic and dynamic similarity conditions. The method of combined control due to creation of swirling of flow in front of impeller and simultaneous change of rotation speed is considered. Analysis of experimental and theoretical results is done. Keywords: centrifugal compressor stage, inlet guide device, axial-radial impeller, gasodynamic performances, whirl of flow. |
34–35 |
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N. A. Raykovskiy The analysis of development of oil-free bearing systems of high-speed compressor and rotary-type power units for mobile operating conditions DOI: 10.25206/2588-0373-2022-6-2-36-49 The article considers an analysis of prospects for the use of oil-free bearings for working conditions in rotary units of autonomous mobile installations. The analysis made it possible to establish the current level of development of oil-free bearing technologies, the existing limitations of their use in units of autonomous mobile installations and urgent problems, the solution of which requires research and further improvement of the designs of bearing units. Keywords: oil-free bearing, rotary units, mobile object, gas lubricant, powder lubricant, magnetic bearing, conditions of application. |
46–49 |
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D. Kh. Sadvakasov, G. I. Chernov, V. L. Yusha The analysis of influence of uncertainty factors on mathematical modeling of the process of reverse expansion of ammonia in low-speed reciprocating compressor stage. Part 2 DOI: 10.25206/2588-0373-2022-6-2-50-58 The paper presents the analysis of influence of the method of calculating the heat transfer coefficient on mathematical modeling of the process of reverse expansion of ammonia in the working chamber of the reciprocating compressor stage (in the area of wet steam). Alternative variants of film and drip schematization of the heat exchange process are considered. The mathematical model is based on the equations of the first law of thermodynamics for a body of variable mass, the equation of state of a real gas, the Clapeyron–Clausius and Newton–Richman equations. Based on the results of the computational and parametric analysis, the applicability of known methods for calculating the heat transfer coefficient to the object under consideration is evaluated. Keywords: ammonia, wet steam, superheated steam, reverse expansion process, mathematical model, heat transfer coefficient, film schematization, drip schematization. |
57–58 |
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A. M. Danilishin, Yu. V. Kozhukhov Numerical simulation of turbulent flow in high-head impeller of centrifugal compressor DOI: 10.25206/2588-0373-2022-6-2-59-70 The paper presents the results of viscous flow modeling using different turbulence models in the Ansys CFX program for the D. Eckardt and H. Krain stage. The impellers are with an outlet angle of 90 and 60 degrees. Isentropic efficiency and the total pressure ratio are compared with the experimental data. The evaluation of the static pressure contours structure at the impeller shroud is made. Recommendations for qualitative modelingof high-head stages are given. Keywords: centrifugal compressor, high-head stage, 3D impeller, CFD, modeling uncertainty. |
69-70 |
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I. Costanzo, S. Murgia, G. Valenti, F. Fasani Experimental investigation on a sliding-vane expander for steam applications / trans. from Engl. M. A. Fedorova DOI: 10.25206/2588-0373-2022-6-2-71-77 There are many industrial plants that use steam as an energy vector at different pressure levels, in which pressure reduction is commonly performed by a throttling valve, resulting a totally irreversible process. It is possible to recover this energy through an expander that generates mechanical or electric energy. This work is focused on the analysis of a highly innovative steam expander based on sliding-vane technology. The design principles of the sliding-vane expander and two experimental campaigns are presented. The first experimental campaign allows to assess the reliability of the system with steam as working fluid, the second campaign leads to assess the stability during long-run and the performance of the system. A maximum expander mechanical power of 28 kW is measured. The pressure-volume diagram of the expansion process is also measured and presented. Keywords: thermal energy recuperation, experimental campaign, boiler, sliding-vane expander, mechanical power, temperature, pressure-volume diagram. Printed by permission from the authors and the Centre for IOP Conference Series Materials Science and Engineering (International Conference on Compressors and their Systems) (London, 2021). |
77 |
AVIATION AND ROCKET-SPACE ENGINEERING
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A. A. Kishkin, A. V. Delkov, Yu. N. Shevchenko, M. U. Abdullaev Velocity coefficient of tangential supply of subsonic centripetal turbine DOI: 10.25206/2588-0373-2022-6-2-78-84 Today, in the spectrum of tasks solved by orbital spacecraft, there is a direction associated with an increase in both functional and thermal power radiated by the thermal control system into outer space. At thermal power more than 7 kW, there is a shortage of heat-radiating surfaces. The problem can be solved in three directions: increasing the temperature of the radiating surface; unfolding additional surfaces; utilization of thermal energy in the organic Rankine cycle. The key link in the implementation of the cycle is the modeling and design of a low-potential jet microturbine. When modeling the working process of such a turbine, a preliminary assessment of energy losses during the formation of a circumferential flow at the impeller inlet is necessary. One of the parameters determining part of the losses is the velocity coefficient φu . This work is devoted to the theoretical substantiation and method of experimental determination of the coefficient in the range of geometric and regime parameters of the tangential supply of a subsonic centripetal turbine. Keywords: jet microturbine, Rankine cycle, geometric and operating parameters, tangential approach, subsonic centripetal turbine, flow energy. |
83-84 |
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V. I. Kuznetsov, V. V. Makarov, A. S. Gritsay Study of characteristics of vortex tube DOI: 10.25206/2588-0373-2022-6-2-85-89 Based on the previously compiled physical and mathematical model of the vortex tube workflow, the calculation of the thermogasodynamic characteristics of the vortex tube with known geometric dimensions and their comparison with experimental data was carried out. The calculations take into account the exchange of work and heat between the axial and peripheral gas layers. The exchange of work is carried out due to the transfer of kinematic energy from the axis to the periphery by viscosity forces when tangential stresses occur. The difference of thermodynamic temperatures when heat is supplied from the periphery to the axis is taken into account. These phenomena reduce the cooling effect of the flow coming out of the diaphragm. Keywords: thermogasodynamic characteristics, viscosity, tangential stresses, temperature efficiency. |
89 |
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A. V. Sedelnikov, E. V. Eskina, A. S. Taneeva, E. S. Khnyryova, E. S. Matveeva The problem of ensuring requirements for microaccelerations on board of small spacecraft DOI: 10.25206/2588-0373-2022-6-2-90-98 The paper provides an overview of ways to reduce micro-accelerations in the internal environment of a small spacecraft and provides quantitative estimates of the level micro-accelerations. The design image of a small technological spacecraft is being formed. The issues of ensuring the quality of the obtained results of gravity- sensitive processes by monitoring the level of micro-accelerations on board small spacecraft are considered. The results obtained can be used in the design and operation of small spacecraft for technological purposes. Keywords: micro-accelerations, gravity-sensitive processes, small spacecraft. |
96-98 |
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E. V. Leun, D. B. Dobriza, А. А. Poliakov, V. К. Sysoev The analysis of features of occurrence of inertial explosion in problems of high-speed impact of metal penetrators into the studied celestial body and meteor-technogenic particles into elements of spacecraft DOI: 10.25206/2588-0373-2022-6-2-99-110 The article discusses the features of the occurrence of an inertial explosion (IE) in the problems of high-speed impacts on a solid barrier of two types of impactors: metal penetrators into the studied celestial body for space contact scientific research and meteor-technogenic particles into the elements of spacecraft. The features of IE, the conditions of its occurrence and the results of theoretical and experimental studies are analyzed. The ratio of the calculated impact velocity, leading to the appearance of willows, to the speed of sound in different metals tending to a certain average value is discussed. The influence of contact and thermoelectric phenomena and the temperature of the impactor on the occurrence of IE, as well as its dependence on the cross-sectional area of the impactor, is discussed.The ways of preventing the occurrence of IE are considered. Keywords: space research, celestial body, penetrator, high-speed impact, overload, critical velocity, electron emission, inertial explosion, meteor-technogenic particles. |
109-110 |