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Wyszukujesz frazę "acoustic cavitation" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
The influence of ultrasound signal parameters on sonoluminescence light intensity
Autorzy:
Szmechta, M.
Boczar, T.
Zmarzły, D.
Powiązania:
https://bibliotekanauki.pl/articles/140426.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diagnostics of insulating oils
sonoluminescence phenomenon
acoustic cavitation
ultrasound signal
acoustic emission Signac
Opis:
Topics of this article concern the study of the fundamental nature of the sonoluminescence phenomenon occurring in liquids. At the Institute of Electrical Power Engineering at Opole University of Technology the interest in that phenomenon known as secondary phenomenon of cavitation caused by ultrasound became the genesis of a research project concerning acoustic cavitation in mineral insulation oils in which a number of additional experiments performed in the laboratory aimed to determine the influence of a number of acoustic parameters on the process of the studied phenomenona. The main purpose of scientific research subject undertaken was to determine the relationship between the generation of partial discharges in high-voltage power transformer insulation systems, the issue of gas bubbles in transformer oils and the generated acoustic emission signals. It should be noted that currently in the standard approach, the phenomenon of generation of acoustic waves accompanying the occurrence of partial discharges is generally treated as a secondary phenomenon, but it can also be a source of many other related phenomena. Based on our review of the literature data on those referred subjects taken, it must be noted, that this problem has not been clearly resolved, and the description of the relationship between these phenomena is still an open question. This study doesn’t prove all in line with the objective of the study, but can be an inspiration for new research project in the future in this topic. Solution of this problem could be a step forward in the diagnostics of insulation systems for electrical Power devices based on non-invasive acoustic emission method.
Źródło:
Archives of Electrical Engineering; 2013, 62, 4; 605-612
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement uncertainty of acoustic emission spectra in cavitating mineral insulating oil
Niepewność pomiaru widm emisji akustycznej podczas kawitacji w mineralnym oleju izolacyjnym
Autorzy:
Szmechta, M.
Zmarzły, D.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/151460.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
analiza widmowa
kawitacja akustyczna
mineralny olej izolacyjny
emisja akustyczna
spectral analysis
acoustic cavitation
mineral insulating oil
acoustic emission
Opis:
The paper presents the research results on acoustic emission signal observed during acoustic cavitation in fresh insulating oil sample. The paper introduces a method of evaluation of measurement uncertainty of acoustic emission spectra by the statistical analysis of series of observations. The drawn probability density functions of used cavitation intensity factor values at different generated source signal parameters show the differences of its uncertainty.
W artykule przedstawiono wyniki pomiarów sygnału emisji akustycznej obserwowanej podczas kawitacji akustycznej w próbce czystego oleju izolacyjnego. Artykuł przybliża przede wszystkim metodę wyznaczania niepewności pomiaru widm emisji akustycznej poprzez analizę statystyczną serii pomiarów. Badania emisji akustycznej dokonano przy wzajemnych kombinacjach następujących wartości skutecznych sygnału: 200 V, 400 V, 600 V, 800 V, 1000 V, 1100 V; oraz jego częstotliwości: 100 kHz, 105 kHz, 110 kHz, 115 kHz. Wykreślone funkcje gęstości prawdopodobieństwa proponowanego wskaźnika intensywności kawitacji przy różnych parametrach źródłowego sygnału pokazują zaobserwowane różnice niepewności pomiaru. Wybór odpowiedniego punktu pracy układu do generacji kawitacji akustycznej pozwala na znaczne ograniczenie niepewności wyznaczania wartości przyjętego wskaźnika intensywności kawitacji poprzez minimalizację wpływu rezonansu naczynia kawitacyjnego.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 2, 2; 146-149
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deagglomeration and Coagulation of Particles in Liquid Metal Under Ultrasonic Treatment
Autorzy:
Kudryashova, Olga
Vorozhtsov, Alexander
Danilov, Pavel
Powiązania:
https://bibliotekanauki.pl/articles/176746.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic field
ultrasonic processing
metal melt
nanoparticles
acoustic coagulation
cavitation
acoustic deagglomeration
Opis:
Ultrasonic processing in the cavitation mode is used to produce the composite materials based on the metal matrix and reinforcing particles of micro- and nano-sizes. In such a case, the deagglomeration of aggregates and the uniform distribution of particles are the expected effects. Although the particles can not only fragment in the acoustic field, they also can coagulate, coarsen and precipitate. In this paper, a theoretical study of processes of deagglomeration and coagulation of particles in the liquid metal under ultrasonic treatment is made. The influence of various parameters of ultrasound and dispersion medium on the dynamics of particles in the acoustic field is considered on the basis of the proposed mathematical model. The criterion of leading process (coagulation or deagglomeration) has been proposed. The calculated results are compared with the experimental ones known from the scientific literature.
Źródło:
Archives of Acoustics; 2019, 44, 3; 543-549
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The possibility of application the acoustic emission method for monitoring flow of water within a ball valve
Autorzy:
Dudzik, K.
Ziegler, B.
Powiązania:
https://bibliotekanauki.pl/articles/245518.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
acoustic emission
AE
diagnostic
ball valve
cavitation
Opis:
Acoustic emission method (AE) can be used for the diagnosis of machine parts or apparatus such as, for example, ball valves. This paper presents the methodology and research results of ball valve in fresh water systems. The opening angle of the valve was changed during the research. The flow of water was measured by a magnetically inductive flowmeter. The research was carried out on a laboratory test stand using an acoustic emission set made by Vallen Inc. This set included: 4 channel signal recorder AMSY 6, two measurement modules ASIP-2/S, preamplifier with a frequency range 20 kHz – 1 MHz and the strengthening of 34 dB and AE signal measurement sensor type VS 150M, with a frequency range 100 – 450kHz. The obtained from the AE-System made by Vallen were compared with the results of the AE-System made by Physical Acoustics (PAC). The PAC system includes preamplifier USB AE Node, type 1283 with bandpass 20 kHz – 1 MHz, AE-Sensor R6D, computer with AE Win for USB Version E5.32 software. During the study, the acoustic emission (AE) generated by flowing water was recorded. The following parameters were determined: amplitude, number of events – hits, the effective value of the signal (RMS). Analysis of the results showed that within a specific range of opening angle of the valve the value of the generated acoustic emission in flowing water increases. This is probably associated with the occurrence of cavitation within the valve. This is an undesirable phenomenon and that these opening angles of ball valve should be avoided in the normal operation.
Źródło:
Journal of KONES; 2016, 23, 4; 87-92
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Diagnostic of Cavitation Flow in the Centrifugal Pump Under Various Impeller Speeds Based on Acoustic Analysis Method
Autorzy:
Al-Obaidi, Ahmed Ramadhan
Powiązania:
https://bibliotekanauki.pl/articles/31339870.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
experimental analysis
impeller speed
cavitation
acoustic signals
Opis:
Condition monitoring in a centrifugal pump is a significant field of study in industry. The acoustic method offers a robust approach to detect cavitations in different pumps. As a result, an acoustic-based technique is used in this experiment to predict cavitation. By using an acoustic technique, detailed information on outcomes can be obtained for cavitation detection under a variety of conditions. In addition, various features are used in this work to analyze signals in the time domain using the acoustic technique. A signal in the frequency domain is also investigated using the fast Fourier method. This method has shown to be an effective tool for predicting future events. In addition, this experimental investigation attempts to establish a good correlation between noise characteristics and cavitation detection in a pump by using an acoustic approach. Likewise, it aims to find a good method for estimating cavitation levels in a pump based on comparing and evaluating different systems.
Źródło:
Archives of Acoustics; 2023, 48, 3; 159-170
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Investigation of the Effect of Suction Valve Opening on the Performance and Detection of Cavitation in the Centrifugal Pump Based on Acoustic Analysis Technique
Autorzy:
Al-Obaidi, Ahmed Ramadhan
Powiązania:
https://bibliotekanauki.pl/articles/176672.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
centrifugal pump
cavitation
suction valve opening
acoustic analysis technique
Opis:
The pump performance and occurrence of cavitation directly depends on different operating conditions. To cover a wide range of operation conditions for detecting cavitation in this work, investigations on the effect of various suction valve openings on cavitation in the pump were carried out. In order to analyse various levels of cavitation in different operation conditions, the effect of the decrease in the inlet suction pressure of the centrifugal pump by controlling the inlet suction valve opening was investigated using this experimental setup. Hence, the acoustic and pressure signals under different inlet valve openings and different flow rates, namely, 103, 200, 302 l/min were collected for this purpose. A detailed analysis of the results obtained from the acoustic signal was carried out to predict cavitation in the pump under different operating conditions. Also, the acoustic signal was investigated in time domain through the use of the same statistical features. The FFT technique was used to analyse the acoustic signal in the frequency domain. In addition, in this work an attempt was made to find a relationship between the cavitation and noise characteristics using the acoustic technique for identifying cavitation within a pump.
Źródło:
Archives of Acoustics; 2019, 44, 1; 59-69
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Comparative Investigations to Evaluate Cavitation Conditions within a Centrifugal Pump Based on Vibration and Acoustic Analyses Techniques
Autorzy:
Al-Obaidi, Ahmed Ramadhan
Powiązania:
https://bibliotekanauki.pl/articles/177056.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
centrifugal pump
cavitation
Fast Fourier Transform
vibration
acoustic
normalise features
Opis:
Cavitation is an essential problem that occurs in all kinds of pumps. This cavitation contributes highly towards the deterioration in the performance of the pump. In industrial applications, it is very vital to detect and decrease the effect of the cavitation in pumps. Using different techniques to analysis and diagnose cavitation leads to increase in the reliability of cavitation detection. The use of various techniques such as vibration and acoustic analyses can provide a more robust detection of cavitation within the pump. In this work therefore, focus is put on detecting and diagnosing the cavitation phenomenon within a centrifugal pump using vibration and acoustic techniques. The results obtained from vibration and acoustic signals in time and frequency domains were analysed in order to achieve better understanding regarding detection of cavitation within a pump. The effect of different operating conditions related to the cavitation was investigated in this work using different statistical features in time domain analysis (TDA). Moreover, Fast Fourier Transform (FFT) technique for frequency domain analysis (FDA) was also applied. Furthermore, the comparison and evaluation system among different techniques to find an adequate technique incorporating for accuracy and to increase the reliability of detection and diagnosing different levels of cavitation within a centrifugal pump were also investigated.
Źródło:
Archives of Acoustics; 2020, 45, 3; 541-556
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of acoustic emission generated by cavitation in insulating oils
Badanie emisji akustycznej generowanej zjawiskiem kawitacji w olejach izolacyjnych
Autorzy:
Zmarzły, D.
Szmechta, M.
Powiązania:
https://bibliotekanauki.pl/articles/151184.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
emisja akustyczna
oleje izolacyjne
kawitacja
acoustic emission
insulating oils
cavitation
Opis:
The main aim of this article is the investigation of acoustic emission signals generated by acoustically induced cavitation in oils. The possibility of using the cavitation phenomenon as a principle of a diagnostic tool for monitoring the condition of insulating oils in power transformers is proposed. In this note, the principles of the measurements method are explained, the built and used experimental apparatus is described and representative results of the experimental data taken from the apparatus are shown. The experimental results are presented in form of power spectral densities of acquired acoustic emission signals. An attempt to approximate the relationship between the power spectral density and the oxidation time of the mineral oil according to the PN-EN 61125 norm was executed.
Podstawą niniejszego artykułu jest badanie sygnałów emisji akustycznej generowanych podczas zjawiska wymuszonej kawitacji akustycznej w olejach. Zaproponowano możliwość wykorzystania zjawiska do diagnostyki właściwości starzeniowych olejów izolacyjnych. Przedstawiono schemat wykorzystywanego układu pomiarowego oraz uzyskane wyniki w postaci widm gęstości mocy sygnału emisji akustycznej dla różnych wartości amplitud sygnału źródłowego. Ponadto dokonano aproksymacji zależności gęstości widmowej mocy wybranych wartości częstotliwości sygnału w funkcji czasu starzenia mineralnego oleju izolacyjnego.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 2, 2; 64-66
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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