Кафедра фізики і електротехніки

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https://elar.khmnu.edu.ua/handle/123456789/577

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Перегляд Кафедра фізики і електротехніки за Автор "Royzman, Vilen"

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  • Ескіз
    Документ
    Balancing of turbomachine rotors by increasing the eccentricity identification accuracy
    (Mechanika, Kaunas, 2016) Goroshko, Andrii; Royzman, Vilen; Ostaševičius, V
    The article presents the results of research aimed at improving the identification of eccentricities by ensuring the stability of solutions of linear discrete inverse problems. The results of the application of scaling factors of systems with a view to reducing their dependence are suggested. Identi-fied eccentricities imbalances and angles of their location allowed to balance the rotor turbopump unit TNA-150 and reduce the maximum deflection of the rotor shaft in the range of 2000-18000 rpm 6 times, the amplitude of vibra-tion supports - 4 times, the static tension in the material of the shaft - 3.5 times, and dynamic tension- 3 times. The use of linear filtering LSEs based on the PCA method, has sig-nificantly reduced the LSE scattering and accurately iden-tify the eccentricities of the compressor rotor of aircraft en-gine AI-20.
  • Ескіз
    Документ
    Construction and practical application of hybrid statisticallydetermined models of multistage mechanical systems
    (Kaunas University of Technology, 2014) Goroshko, Andrii; Royzman, Vilen
    The paper proposes a method of creating a hybrid statistically-determined models for structurally complex of mechanical systems. The method uses an active planned experiment , but it can significantly reduce the amount of experimental research. Hybrid statistically-determined model of aircraft defendant signal power was created. Priority factors of mechanical nature destabilizing the output power level were identified. The study solved multiple inverse problem of determining the permissible values of these factors, in which the signal power is within specifications.
  • Ескіз
    Документ
    Increase in Solution Stability of Ill Conditioned Dynamics Problems
    (Allerton Press, Inc., 2016-06) Goroshko, Andrii; Royzman, Vilen
    The difficulties of design determination of the quantitative characteristics of weight, elas ticity, damping, critical frequencies of fast revolving rotors are demonstrated. It is suggested to use two approaches in order to obtain accurate and stable solutions of ill conditioned reverse problems of rotor dynamics. The first one concerns the reduction of design model size. It is shown that relatively uncom plicated design rotor models are used as they were considered the most effective and stable, and match the selected design scheme and parameter values (hardness, weights, deflections, etc.) obtained as a result of experiments or calculations. The second approach deals with statistical method of the increase of solution stability. Its efficiency was shown while identifying rotor eccentricity by the exam ple of five mass rotor model.
  • Ескіз
    Документ
    Quality and Reliability of Technical Systems: Theory and Practice
    (JVE International Ltd, 2018-08) Goroshko, Andrii; Royzman, Vilen; Zembytska, Maryna
    The monograph provides original approaches to the quality and reliability improvement in mechanical engineering, taking into account the functionally oriented management. The outlined studies validate the methods facilitating the increased reliability and durability of rotor systems and vibration processes. Methods for increasing the reliability and wear resistance of machine parts and units under dynamic and shock loads are considered and proposed. The issues of creation of new materials in mechanical engineering, in particular, nanostructures are studied and investigated. New quality and reliability improving methods for electronic equipment and energy systems are offered. The research also considers the issues of reliability and durability of construction materials. The monograph is intended for scientists, graduate students and professionals in the field. It may also be useful to students of technology.
  • Ескіз
    Документ
    Statistical Methods for Providing the Stability of the Solutions of Inverse Problems and Their Application to Decrease Rotor Vibroactivity
    (Allerton Press, Inc., 2015) Goroshko, Andrii; Royzman, Vilen
    Many machine design problems relate to the class of inverse problems, whose solution is reduced to the solution of systems of linear algebraic equations. The relation between the matrix con ditionality number of such systems and solution errors is shown in this article. The application of the least square method to improve the accuracy of solutions is justified. A method for providing the sta bility of solutions of systems of linear algebraic equations based on the use of additional information by increasing the number of measurements of initial parameters is proposed. The approach and statis tical algorithm for achieving a given accuracy of the solution of poorly specified systems of linear alge braic equations are developed. The results of using the offered methods for the identification of eccen tricities and elastic inertial parameters in the problem of decreasing the vibroactivity of the rotor of tur bine pump are given.