Diagnostics of Advanced Power Intensive Power Sources Based on the Acoustic Spectroscopy Method

2021 ◽  
pp. 121-127
Author(s):  
E.M. Petrenko ◽  
V.A. Semenova
Keyword(s):  
High Reliability ◽  
Methodological Approach ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Mechanical Action ◽  
Mean Value ◽  
Spectroscopy Method ◽  
Power Sources ◽  
Acoustic Spectroscopy ◽  
Noise Diagnostics

Objective of this article is to develop a method for lithium chemical current sources diagnostics, which would ensure high reliability in assessing their technical state (primarily, the discharge degree) close to potentially achievable introduction of the acoustic spectroscopy method. Today, microcalorimetric studies and methods of impedance and noise spectroscopy make it possible to predict the lithium chemical current sources service life. However, implementation of the microcalorimetric studies result requires a lot of time accompanied by using stationary and large-size equipment, which is practically impossible in the autonomous conditions. Application of the impedance spectroscopy method provides satisfactory results only with high degrees of discharge. In the range of 0--30 %, it is very difficult to determine the discharge degree, since noticeable alteration in the correlate within its deviation from the mean value is missing. In this regard, it is proposed in order to provide diagnostics of the lithium chemical current sources in the region of initial degrees of discharge to introduce the noise diagnostics method. In order to increase reliability of the diagnostic estimates, it is advisable to use acoustic spectroscopy as a physically independent method in diagnosing the state of lithium chemical current sources. Results of the preliminary measurements analysis confirm the prospects of using the acoustic spectroscopy method in assessing the current state of primary lithium chemical current sources. Experimental studies of the lithium chemical current sources response to acoustic (mechanical) action made it possible to determine a set of parameters characterizing the proposed methodological approach. This provided a possibility to search for correlation dependences of the lithium chemical current sources spectral characteristics on the degree of their discharge. This makes it possible to use the method of acoustic spectroscopy in prompt and reliable diagnostics of the primary current sources in the region of low discharge degrees

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

ANALYSIS OF THE ERROR IN DETERMINING THE EQUIVALENT SIZE OF A DEFECT BY THE STANDARDLESS METHOD DURING ULTRASONIC TESTING

2021 ◽  
pp. 50-57
Author(s):  
A. N. Kireev ◽  
M. A. Kireeva
Keyword(s):  
Relative Error ◽  
High Reliability ◽  
Ultrasonic Method ◽  
Experimental Studies ◽  
Standard Samples ◽  
Defect Identification ◽  
Identification Method ◽  
Maximum Value ◽  
Software Product ◽  
The Relationship

The article provides a review and analysis of the defect identification method for determining the size of discontinuities when diagnosing various machine parts and units by the manual ultrasonic method. This method makes it possible to determine the equivalent size of discontinuities of various types without using standard samples of an enterprise: point planar and volumetric; extended planar and volumetric. The method is based on the use of the relationship between the amplitude and time characteristics of the echo signal from the discontinuity and the backside signal in the object being diagnosed and the equivalent size of the discontinuity. The article presents the mathematical apparatus for the implementation of this method. Also presented is a software product that allows you to automate calculations when using this defect identification method. The article contains experimental studies of the method for determining the equivalent dimensions of discontinuities of various types, which have shown its high reliability. The maximum value of the relative error in determining the equivalent size of a point planar discontinuity was 2.867 %. The maximum value of the relative error in determining the equivalent size of a point volumetric discontinuity was 1.986 %. The maximum value of the relative error in determining the transverse equivalent size of an extended planar discontinuity was 0.667 %. The maximum value of the relative error in determining the transverse equivalent size of an extended volumetric discontinuity was 1.95 %.

Chemical Current Source Express Diagnostics Using Noise Spectroscopy on the Example of Lithium-Thionyl Chloride Battery

2021 ◽  
pp. 136-143
Author(s):  
E.M. Petrenko ◽  
V.A. Semenova
Keyword(s):  
Thionyl Chloride ◽  
Discharge Rate ◽  
Current Source ◽  
Mean Value ◽  
Spectroscopy Method ◽  
Discharge Process ◽  
Absolute Deviation ◽  
Chemical Current Source ◽  
Measurement Analysis ◽  
Noise Spectroscopy

Lithium-thionyl chloride battery voltage is practically not changing during the discharge process and drops sharply being completely discharged. In this regard, the problem of non-destructive quality control of the chemical current sources (first of all, the discharge degree) before installation thereof in the equipment becomes of particular importance. Microcalorimetric studies make it possible to rather correctly determine the current source internal self-discharge rate, predict the LCCS shelf life and its performance term. However, the heat release absolute value in current sources with sufficient storability, i.e., with low self-discharge, is very small; therefore, it is necessary to use sensitive, stationary and large-sized equipment. This makes such diagnostics impossible when operating in the stand-alone conditions. The impedance spectroscopy method could be proposed to solve this problem. However, satisfactory results are only obtained in the 0--70 % residual capacitance range. Determination of residual capacitance in the 70--100 % range appears to be rather difficult due to the absence of noticeable alteration in the informative parameter within the limits of its absolute deviation from the mean value. In this regard, it looks advisable to use noise spectroscopy as a physically independent method in diagnosing the state of chemical current sources to expand the residual capacitance diagnostics range to the 70--100 % domain, as well as to increase reliability of the chemical current source diagnostic estimate in the range of 50--70 %. Results of the electrochemical noise measurement analysis confirm promising application of the noise spectroscopy method in estimating current state of the primary chemical current sources in their low discharge domains

Microgrid Model on Homer Software

2021 ◽  
Vol 9 (VI) ◽  
pp. 757-760
Author(s):  
Mohd Ahamad
Keyword(s):  
Power Generation ◽  
Power Electronics ◽  
Life Cycle Cost ◽  
Low Voltage ◽  
High Reliability ◽  
Low Cost ◽  
Local Area ◽  
New Paradigm ◽  
Power Sources ◽  
Wide Range

A new concept in power generation is a microgrid. The Microgrid concept assumes a cluster of loads and microsources operating as a single controllable system that provides power to its local area. This concept provides a new paradigm for defining the operation of distributed generation. The microsources of special interest for MGs are small (<100-kW) units with power electronic interfaces. These sources are placed at customers sites. They are low cost, low voltage and have a high reliability with few emissions. Power electronics provide the control and flexibility required by the MG concept. A properly designed power electronics and controllers insure that the MG can meet the needs of its customers as well as the utilities. The goal of this project is to build a complete model of Microgrid including the power sources, their power electronics, and a load and mains model in THE HOMER. The HOMER Micropower Optimization Model is a computer model developed by the U.S. National Renewable Energy Laboratory (NREL) to assist in the design of micropower systems and to facilitate the comparison of power generation technologies across a wide range of applications. HOMER models a power system’s physical behavior and its life-cycle cost, which is the total cost of installing and operating the system over its life span. HOMER allows the modeler to compare many different design options based on their technical and economic merits. It also assists in understanding and quantifying the effects of uncertainty or changes in the inputs.

Using compatibility charts to optimize research into fire retardants

2021 ◽  
Vol 29 (6) ◽  
pp. 40-49
Author(s):  
T. Yu. Eremina ◽  
D. A. Korolchenko ◽  
F. A. Portnov
Keyword(s):  
Research Methods ◽  
Interdisciplinary Research ◽  
Building Materials ◽  
Design Research ◽  
Methodological Approach ◽  
Experimental Studies ◽  
Assessment Method ◽  
Material Research ◽  
Fire Retardants ◽  
Interdisciplinary Methods

Introduction. Interdisciplinary research is a most relevant issue in science and education. The integration of intellectual resources with research and production infrastructure is acknowledged as the main goal of interdisciplinary research in the international practice. The main (analytical) part. The authors propose the following methodological approach to the study, based on the distribution of interdisciplinary methods into groups by the scale of the research subject (material). In this case, the studies have the following levels: microlevel, supramolecular level, material research, design research. The paper presents research methods used at each of these levels. The co-authors propose to optimize the study of performance characteristics of building materials and fire retardants through the use of a compatibility chart with regard for the study levels and the analysis of methods of experimental research at each level. Using a compatibility chart. The methodology of the study. A research into the fire retardant efficiency of esters of phosphoric acid, used to modify wood, was selected as a practical example for compatibility diagrams. The project encompasses a number of methods applicable to compatibility charts: the method of elemental analysis, the Gibbs energy assessment method, the sample surface assessment method, the electron microscopy method, methods of assessing fire-hazardous characteristics of wood, the water sorption method, strength and biosecurity assessment methods. Conclusions. The co-authors first proposed an algorithm for generalizing the empirical data on mechanochemical characteristics of materials using interdisciplinary methods in the form of a compatibility chart. This methodology optimizes research into any composite materials though it preserves targeted research methods and eliminates impractical and concomitant experimental studies, thus, reducing labour costs and environmental impacts.

scholarly journals 3DOF Ultrasonic Motor with Two Piezoelectric Rings

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 834 ◽  
Author(s):  
Vytautas Jūrėnas ◽  
Gražvydas Kazokaitis ◽  
Dalius Mažeika
Keyword(s):  
Numerical Simulation ◽  
Magnetic Dipole ◽  
Attitude Control ◽  
Degrees Of Freedom ◽  
High Reliability ◽  
Experimental Studies ◽  
Main Idea ◽  
Ultrasonic Motor ◽  
Response Analysis ◽  
Magnetic Sphere

A novel design of a multiple degrees of freedom (multi-DOF) piezoelectric ultrasonic motor (USM) is presented in the paper. The main idea of the motor design is to combine the magnetic sphere type rotor and two oppositely placed ring-shaped piezoelectric actuators into one mechanism. Such a structure increases impact force and allows rotation of the sphere with higher torque. The main purpose of USM development was to design a motor for attitude control systems used in small satellites. A permanent magnetic sphere with a magnetic dipole is used for orientation and positioning when the sphere is rotated to the desired position and the magnetic field synchronizes with the Earth’s magnetic dipole. Also, the proposed motor can be installed and used for robotic systems, laser beam manipulation, etc. The system has a minimal number of components, small weight, and high reliability. Numerical simulation and experimental studies were used to verify the operating principles of the USM. Numerical simulation of a piezoelectric actuator was used to perform modal frequency and harmonic response analysis. Experimental studies were performed to measure both mechanical and electrical characteristics of the piezoelectric motor.

scholarly journals Self-oscillations at the frequency of subharmonics in nonlinear electric chains and systems

2019 ◽  
Vol 139 ◽  
pp. 01054 ◽  
Author(s):  
M.I. Ibadullaev ◽  
A.N. Tovbaev ◽  
A.Zh. Esenbekov
Keyword(s):  
Single Phase ◽  
Experimental Studies ◽  
Power Lines ◽  
Equivalent Model ◽  
Critical Parameters ◽  
Steady State Mode ◽  
Power Sources ◽  
Electric Circuits ◽  
Three Phase ◽  
Extensive Class

It is known that the occurrence and existence of autoparametric oscillations (AIC) at the subharmonic frequency (GHC) in power lines (power lines) and in power supply systems is extremely undesirable, since they cause ferroresonant overvoltages at different frequencies. At the same time, there is an extensive class of nonlinear electric circuits in which the excitation of the AIC at the frequency of the SGC forms the basis of frequency-converting devices serving as secondary power sources. It is shown that single-phase-three-phase nonlinear systems are, to one degree or another, equivalent circuits of power lines, the main elements of which are: longitudinal compensation capacitors, transverse compensation reactors, and transformers with non-linear characteristics. The regularities of the excitation of the GCC at the frequency (ω / 3) of the power lines were studied, theoretical and experimental studies of the equivalent model of single-phase-three-phase circuits with nonlinear inductance were carried out. For a theoretical analysis of the steady-state mode of SGK at a frequency (ω / 3) with inductive coupling, the frequency- energy approach is used. The conditions of existence and critical parameters of the circuit are determined, and the mechanism of the appearance of the SGC at the frequency (ω / 3) is also studied.

Application of three-dimensional resonant acoustic spectroscopy method to rock and building materials

2001 ◽  
Vol 110 (4) ◽  
pp. 1770-1777 ◽  
Author(s):  
Lev Ostrovsky ◽  
Andrey Lebedev ◽  
Alexander Matveyev ◽  
Andrey Potapov ◽  
Alexander Sutin ◽  
...  
Keyword(s):  
Building Materials ◽  
Three Dimensional ◽  
Spectroscopy Method ◽  
Acoustic Spectroscopy

scholarly journals РЕКОМЕНДАЦИИ ПО ПРОЕКТИРОВАНИЮ ГИДРОСТАТОДИНАМИЧЕСКИХ ПОДШИПНИКОВ СКОЛЬЖЕНИЯ СДВОЕННОГО ТИПА

2020 ◽  
pp. 100-105
Author(s):  
Владимир Иосифович Назин
Keyword(s):  
Dynamic Characteristics ◽  
Fluid Layer ◽  
High Reliability ◽  
Experimental Studies ◽  
Working Fluid ◽  
Stable Operation ◽  
Static And Dynamic Characteristics ◽  
Start Up ◽  
Bearing Materials

The task is to develop recommendations for the design of dual-type hydrostatodynamic plain bearings based on the existing experience in designing this type of plain bearings, as well as based on many theoretical and experimental studies performed by the author of this work. The number of the most necessary parameters for the design of dual-type hydrostatodynamic bearings is determined. Particular attention was paid to the development of recommendations for additional parameters specific to the design of double type plain bearings. Attention is paid to the selection of double-type bearing materials and it is shown that the problem of selecting materials for hydrostatic dynamic bearings is not so relevant, however, sometimes in start-up and shutdown modes, as well as in emergencies, to ensure high reliability of the designed machine, it is necessary to pay attention to the choice of bearing materials. The influence of various forms of chambers on the static and dynamic characteristics of hydrostatodynamic bearings is analyzed and it is shown that the greatest distribution in practice, they got rectangular cameras. It is shown that the flow regime of the working fluid also significantly affects both the static and dynamic characteristics of the bearing. It is noted that even with a non-rotating rotor in a hydrostatodynamic bearing, the most turbulent mode of flow of the working fluid is most often observed. The influence of the thickness of the working fluid layer on increasing the rigidity of the supports and expanding the range of stable operation is considered. It is shown that with a decrease in the clearance in the bearing, its bearing capacity increases and the range of stable operation expands, however, this increases the friction power loss, increases the likelihood of clogging of the slit bearing path, and also increases the requirements for the quality of manufacture of the bearing working surfaces. It is recommended that in the double hydrostatodynamic bearing in the outer and inner parts to assign the same clearances. It is shown that in a dual hydrostatodinamic bearing, the existing recommendation on the number of chambers can lead in some cases to large working fluid flow.

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