scholarly journals SYNTHESIS OF METHODS OF EVALUATION OF ELECTROMAGNETIC COMPATIBILITY OF RADIO-TECHNICAL SYSTEMS

2019 ◽  
pp. 57-65
Author(s):  
Natali Lukova-Chuiko ◽  
Volodymyr Nakonechnyi ◽  
Volodymyr Saiko ◽  
Serhii Toliupa
Keyword(s):  
Electromagnetic Fields ◽  
Electromagnetic Compatibility ◽  
Operating Conditions ◽  
Design Stage ◽  
Quality Level ◽  
Radio Engineering ◽  
Radio Electronic ◽  
Modern Development ◽  
Radio Equipment ◽  
Characteristic Features

Modern development of radio equipment is characterized by an increase in the speed of processes of transmission and processing of information, miniaturization and integration into unified complexes that physically bridles the sources and receptors of interference. All this leads to the strengthening of the requirements to ensure compliance with the conditions of electromagnetic compatibility and the need for its evaluation at the design stage of radio engineering devices and systems, because the incomplete or incorrect assessment of these requirements leads to a significant increase in time and material costs of the manufacturer, for further development of the development of electronic equipment and reduction its competitiveness. Widespread use of different purposeful electronic means leads to an increase in the levels of electromagnetic fields created by them in the surrounding space. These fields are obstacles for other similar devices, may degrade the operating conditions and reduce the effectiveness of their use. In this process, it is easy to see the characteristic features of dialectical development - progress in this area is restrained by the negative phenomena generated by its development. Further progress requires the overcoming of this trend, that is, development on a new quality level, which is to ensure the joint operation of various means. The key is that the actions of the electromagnetic fields, which are created by some technical means to the other, are carried out for the transmission of information, its processing, or vice versa, violation of the process of transmission and processing of data. Therefore, an analysis is proposed that allows preliminary prediction of the fulfillment of the conditions of electromagnetic compatibility in a group of radio-electronic means that have a number of sources of interference and radio engineering devices on which they affect. In this case, the important issue of checking the provision of electromagnetic compatibility of radio-electronic means is to determine the magnitude of the permissible power at which provides electromagnetic compatibility. The purpose of this article is to consider, from the general positions, the main tasks of the analysis and evaluation of the electromagnetic compatibility of radio-electronic means

scholarly journals Calculated estimation of electromagnetic compatibility of radio-electronic means of space systems and complexes

2021 ◽  
Vol 24 (2) ◽  
pp. 49-54
Author(s):  
Yevgeny E. Krivobokov
Keyword(s):  
Electromagnetic Compatibility ◽  
Mutual Influence ◽  
Integrated Approach ◽  
Design Stage ◽  
Launch Vehicles ◽  
Space Systems ◽  
Space Technology ◽  
Radio Electronic ◽  
Analytical Assessment ◽  
Technical Measures

This article presents the methods of complex computational and analytical assessment of ensuring electromagnetic compatibility of technical means (electrical, electronic and radio-electronic means of launch vehicles and spacecraft). These methods allow us to conduct a comprehensive computational and analytical assessment of the electromagnetic compatibility of the technical means of rocket and space technology, which in its essence allows us to assess the mutual influence of the technical means of rocket and space technology already at the design stage of rocket and space technology objects. The analysis of the results of the assessment of the electromagnetic compatibility of the technical means of rocket and space technology allows us to develop organizational and technical measures aimed at ensuring the electromagnetic compatibility of the technical means of rocket and space technology at all stages of the life cycle of objects of rocket and space technology. To assess the electromagnetic compatibility of the technical means of rocket and space technology, an integrated approach was chosen due to the large dimension of the initial data and the variety of possible variants of interference penetration.

ABOUT MATERIALS OF THE THERMOEMISSION COOLING SYSTEM OF BLADES OF TURBINES OF GAS TURBINE CONVERTERS OF AEROSPACE CRAFTS OF RADIO-ELECTRONIC REMOTE SENSING OF THE EARTH

2018 ◽  
pp. 89-95
Author(s):  
A. V. Kolychev ◽  
V. A. Kernozhitskiy ◽  
A. A. Levikhin
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Turbine Blades ◽  
Thermionic Emission ◽  
Ceramic Materials ◽  
Operating Conditions ◽  
Inert Gases ◽  
Thermal Electron ◽  
Radio Electronic ◽  
Radio Equipment

Rated estimates of effect of application of the Thermal electron emission Way of Cooling (TWC) of blades of turbines (BT) of the gas turbine converters (GTC) of the Space Aircraft (SA) developed in in D. F. Ustinov Baltic State Technical University «VOENMEH» are given in the present article. Relevance of development of TWC is confirmed by the fact that now in the Russian Federation development of the SA platform with the energy basis at the heart of which the principle of gas turbine transformation is conducted. However, because of low reliability of its basic elements - blades of turbines in operating conditions, it is necessary to reduce temperature in installation that reduces efficiency and increases the weight and dimensions of SA in general. It means that taking into account opportunities of modern means of removal, opportunities for equipment of SA of the radio-electronic equipment are reduced and characteristics of SA with radio equipment in general decrease. Improvement of these characteristics requires increase of reliability of blades of turbines and increase on this basis of temperature of GTC, its efficiency with simultaneous decrease in weight and dimensions. But in this case it is supposed that turbine blades will be made of the ceramic materials functioning in the environment of the inert gases heated from onboard source of heat energy. One of problems at the same time is emergence of temperature gradients, tension and deformations that can lead to emergence of cracks. However, if to execute ceramic blades from metalsimilar connections (borida, carbides, alloys of borid and carbides) using TWC, then opportunity essential (more, than twice) decrease in both TB temperature, and temperature differences, and tension in TB design appears. In article it is also shown that decrease in temperature stresses in design of hot elements at equivalent heat load is reached due to fundamental properties of thermionic emission, namely thanks to dependence of intensity of thermionic emission and electronic cooling on temperature.

scholarly journals Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 759
Author(s):  
Andrea Mariscotti
Keyword(s):  
Time Distribution ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Transportation Systems ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Intrinsic Variability ◽  
Statistical Characterization ◽  
Electromagnetic Emissions

Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity. The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches. Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts. This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena). In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, e.g., by means of Amplitude Probability Distribution and including time distribution information. The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (e.g., rolling stock operating conditions, synchronization issues, and electric arc intermittence).

scholarly journals Managing energy performance in buildings from design to operation using modelling and calibration

2021 ◽  
pp. 014362442110083
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Dejan Mumovic ◽  
Mike Davies
Keyword(s):  
Best Practice ◽  
Good Practice ◽  
Energy Performance ◽  
Operating Conditions ◽  
Design Stage ◽  
Performance Gap ◽  
Actual Performance ◽  
Simulation Tools ◽  
Calibration Protocol ◽  
Covering Design

To manage the concerns regarding the energy performance gap in buildings, a structured and longitudinal performance assessment of buildings, covering design through to operation, is necessary. Modelling can form an integral part of this process by ensuring that a good practice design stage modelling is followed by an ongoing evaluation of operational stage performance using a robust calibration protocol. In this paper, we demonstrate, via a case study of an office building, how a good practice design stage model can be fine-tuned for operational stage using a new framework that helps validate the causes for deviations of actual performance from design intents. This paper maps the modelling based process of tracking building performance from design to operation, identifying the various types of performance gaps. Further, during the operational stage, the framework provides a systematic way to separate the effect of (i) operating conditions that are driven by the building’s actual function and occupancy as compared with the design assumptions, and (ii) the effect of potential technical issues that cause underperformance. As the identification of issues is based on energy modelling, the process requires use of advanced and well-documented simulation tools. The paper concludes with providing an outline of the software platform requirements needed to generate robust design models and their calibration for operational performance assessments. Practical application The paper’s findings are a useful guide for building industry professionals to manage the performance gap with appropriate accuracy through a robust methodology in an easy to use workflow. The methodological framework to analyse building energy performance in-use links best practice design stage modelling guidance with a robust operational stage investigation. It helps designers, contractors, building managers and other stakeholders with an understanding of procedures to follow to undertake an effective measurement and verification exercise.

Frequency selective antenna radome based on metal-dielectric gratings and perforated screens

Antennas ◽  
2021 ◽  
Author(s):  
A. O. Kasyanov
Keyword(s):  
Antenna Arrays ◽  
Electromagnetic Compatibility ◽  
Numerical Study ◽  
Numerical Data ◽  
Microwave Antenna ◽  
Frequency Selective Surfaces ◽  
Radio Electronic ◽  
Dielectric Gratings ◽  
Study Results ◽  
Frequency Selective

This article is devoted to the analysis of numerical study results of printed frequency selective surfaces scattering characteristics. It has been shown that these frequency selective surfaces may be used as antenna radomes. Numerical results have been obtained by full-wave simulation of frequency-selective surfaces with dielectric covers. The numerical research results of the scattering characteristics of printed frequency selective surfaces as antenna radomes based on metal-dielectric gratings and thick perforated screens have been presented. A comprehensive numerical study of microwave frequency selective surfaces based on multi-element multilayer printed reflectarrays and thick perforated screens has been carried out. Constructive solutions for metal-dielectric structures in integral design, realizing the functions of frequency selective surfaces, have been found. These solutions are based on performed numerical studies. The problems of constructive implementation of multilayer planar spatially selective as frequency selective surfaces have been considered. These frequency selective surfaces are integrated into radiation systems of modern multi-element printed phased arrays. The problems connected with creation of such arrays have been also considered. The numerical simulation results for frequency selective surfaces based on metal gratings with dielectric covers have been obtained. These results can be used to select the most rational options for the topology of metal-dielectric gratings. Such solutions may be useful for design of multifunctional radomes in microwave antenna systems. Based on the obtained numerical data, the possibilities of using flat gratings as frequency selective surfaces in the composition of antenna radomes have been considered. The spatial frequency-selective structures proposed in this work are performed as multi-planar printed gratings. These gratings are designed to ensure electromagnetic compatibility of closely spaced radio electronic sets. These radio electronic sets operate in close frequency ranges. They contain antenna arrays. These arrays are placed under the antenna radomes.

CFD Investigation of Downhole Natural Gas Separation Efficiency in the Churn Flow Regime

2021 ◽  
Author(s):  
Charles Okafor ◽  
Patrick Verdin ◽  
Phill Hart
Keyword(s):  
Natural Gas ◽  
Flow Regime ◽  
Gas Separation ◽  
Separation Efficiency ◽  
Operating Conditions ◽  
Analytical Models ◽  
Design Stage ◽  
Average Error ◽  
Multiphase Model ◽  
Churn Flow

Abstract Downhole Natural Gas Separation Efficiency (NGSE) is flow regime dependent, and current analytical models in certain conditions lack accuracy. Downhole NGSE was investigated through 3D Computational Fluid Dynamics (CFD) transient simulations for pumping wells in the Churn flow regime. The Volume of Fluid (VOF) multiphase model was considered along with the k – ε turbulence model for most simulations. A mesh independence study was performed, and the final model results validated against experimental data, showing an average error of less than 6 %. Numerical simulation results showed that the steady state assumption used by current mathematical models for churn flow can be inaccurate. Several key parameters affecting the NGSE were identified, and suggestions for key improvements to the widely used mathematical formulations for viscous flow provided. Sensitivity studies were conducted on fluid/geometric parameters and operating conditions, to gain a better understanding of the influence of each parameter on NGSE. These are important results as they equip the ESP engineer with additional knowledge to maximise the NGSE from design stage to pumping operations.

scholarly journals Material Origins of Accelerated Operational Wear of RD-33 Engine Blades

2020 ◽  
Author(s):  
Adam Kozakiewicz ◽  
Stanislaw Jóźwiak ◽  
Przemysław Jóźwiak ◽  
Stanisław Kachel
Keyword(s):  
Chemical Composition ◽  
Construction Material ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Jet Engine ◽  
Emergency Situations ◽  
Low Pressure Turbine ◽  
Propulsion Unit ◽  
Selection Of

The structural and strength analysis of the material used to construct such an important engine element as the turbine is of great significance, both at the design stage as well as during tests and expertises related to emergency situations. Bearing in mind the conditions above mentioned, the paper presents the results of research on the chemical composition, morphology and phased structure of the metallic construction material used to produce the blades of the high and low pressure turbine of the RD-33 jet engine, which is the propulsion unit of the MiG-29 aircraft. The data obtained as a result of the material tests of the blades allowed, on the basis of the analysis of chemical composition and phased structure, to determine the grade of the alloy used to construct the tested elements of the jet engine turbine. The structural stability of the material was found to be lower in comparison with engine operating conditions, which manifested itself as a clear decrease in the resistance properties of the blade material. The results obtained can be used as a basis for analyzing the life span of an object or a selection of material replacements, which enable to produce the analyzed engine element.

scholarly journals The Business Service Sector in India, Ireland and Poland. A Comparative Analysis

2019 ◽  
Vol 22 (2) ◽  
pp. 159-172
Author(s):  
Arkadiusz Mroczek
Keyword(s):  
Comparative Analysis ◽  
Service Sector ◽  
Operating Conditions ◽  
Business Service ◽  
Literature Study ◽  
Location Factors ◽  
Current Growth ◽  
Characteristic Features ◽  
Selection Of ◽  
Made In

The fast growth of the service sector is one of the characteristic features of the contemporary economy. Amongst other CEE countries, Poland is one of the emerging locations for this sector. The aim of the paper is to examine and compare the business service sector in India, Ireland and Poland. Both India and Ireland are exceptional locations for this industry, so comparing the state and operating conditions in Poland with those countries can be insightful. A literature study is used to determine the motives of companies undertaking offshore investments, upon which a selection of location factors is made. In the empirical part, those factors are analyzed in a descriptive way. This allows us to draw conclusions concerning this sector in Poland. This country, to some extent, possesses selected positive features of both India and Ireland, which explains the current growth of the sector.

scholarly journals Hydrodynamic and hydrostatic forces as factors affecting tailing dump stability

2021 ◽  
Vol 44 (1) ◽  
pp. 63-72
Author(s):  
D. Sh. Sharipov
Keyword(s):  
Research Methods ◽  
Operating Conditions ◽  
Design Stage ◽  
Tailing Dump ◽  
Initial Development ◽  
Technical Problems ◽  
Factors Affecting ◽  
Deformation Processes ◽  
Tailing Dams ◽  
The Impact

The study of the processes occurring deep in the earth's crust has always been a relevant research topic. The results of these studies allowed development and safe mining of mineral deposits in various conditions. The growth in the consumption of extracted resource and the increase in the scale of mining are forcing enterprises to search for the solutions to complex engineering and technical problems, one of which is the problem of displacement of rock masses and the earth's surface in industrial production-affected areas including tailings dams. The purpose of this study is to improve the operation safety of tailing dams. The object of the study is embankment dams of dressing plant tailing dumps. The subject of the study is deformation processes occurring in dam bodies and slope surfaces. The main research methods used in the work are: the study of safe operation methods for tailing dams based on the operating conditions of Uchalinskoye tailing dump using the modern methods of stability assessment, analysis and generalization of domestic and foreign experience, as well as the study of current methods of geomechanical monitoring of deformation processes – engineering and geological, geophysical, mine surveying and hydrogeological ones. The article describes geographic, hydrographic, climatic, geological and mining operation conditions of the tailing dump of Uchalinsky GOK (Ore Mining and Processing Plant) JSC. The influence of hydrodynamic and hydrostatic forces on embankment tailing dam stability is substantiated. Based on the data obtained and the research methods used, it is concluded that hydrodynamic and hydrostatic forces are fundamental destructive factors affecting dams. The results of these studies can be applied at the design stage of hydraulic structures, since they will supplement theoretical knowledge about the impact of liquid waste on the safety of tailing dams and earth-filled dams, as well as allow detecting deformation processes at their initial development stage and making decisions on their elimination.

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