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Wyszukujesz frazę "insulation" wg kryterium: Temat


Tytuł:
Effect of Diffusing Elements in a Reverberation Room on the Results of Airborne Sound Insulation Laboratory Measurements
Autorzy:
Mleczko, Dominik
Wszołek, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/177423.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
reverberation room
airborne sound insulation
diffuseness
Opis:
The main problem in the measurement of airborne sound insulation is the measurement of the sound power radiated by the barrier, in practice performed by measuring the sound pressure level and the acoustic absorption in the receiving room. Large variations of the sound pressure level in a reverberation room indicate the presence of dominating strong standing waves, so that it becomes necessary to install diffusing elements. In ISO 10140, the limits have been defined in which the reverberation time at frequencies at and above 100 Hz should be included. Sometimes, however, in the case of rooms with a large volume, obtaining the required parameters is difficult and sometimes even impossible. It should then be checked whether the measured sound insulation depends on the reverberation time. The paper presents the results of sound insulation measurements at various reverberation time lengths in subsequent stages of diffusing elements installation in the receiving room. An analysis of diffusing materials amount and arrangement influence on the uniformity of the sound pressure level distribution and reverberation time in the room as well as the value of the measured sound insulation was carried out. Uncertainty of sound insulation measurement with partial uncertainties was adopted as a criterion supporting the assessment of the obtained results.
Źródło:
Archives of Acoustics; 2019, 44, 4; 739-746
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Possibility of Limiting the Impact of Ground Vibrations Caused During Demolition of a Towers on Environment
Autorzy:
Targosz, J.
Bednarz, J.
Lisowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/177131.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ground vibrations
insulation layers
vibrations measurements
Opis:
Before disassemble and demolition of five granulation towers the authors planned and carried out measurements of the intensity of vibrations induced during the fall of the dismantled components of towers on the ground. The main aim of the study was to determine the maximum permissible weight of falling elements of the towers during the demolition, in terms of ensuring the protection of buildings and equipment located in the vicinity of the works. It was unacceptable to increase the vibration amplitudę displacement in each section of measurement on each of the three perpendicular axes by more than 2 µm peak-to-peak value and the absolute velocity of RMS of vibration amplitude couldn’t be increased by more than 1 mm/sec value than the background vibration during the demolition of the towers. Preliminary experimental studies were conducted on a test stand and the measurements were made on the real object. The amplitudes of vibration waves displacement and velocity were recorded on the measurement section in the direction of the protected building. The results of measurements were used to identify the propagation of the shock wave and the effectiveness of the proposed insulation layers.
Źródło:
Archives of Acoustics; 2016, 41, 4; 649-657
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and Experimental Verification of Ultrasound Transmission in Electro Insulation Oil
Autorzy:
Wotzka, D.
Cichoń, A.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/177158.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound transmission
numerical simulations
electro-insulation oil
Opis:
A verification study of ultrasound transmission numerical simulation results with experiment results is presented in this paper. The work considers a model of a transformer tank which is filled with electro insulating oil. In the experiment, performed under laboratory conditions, an ultrasound wave is generated by a piezoelectric transducer that is fixed in the centre of the tank and measured by another transducer mounted inside the tank at three distances: 10, 20 and 30 cm from the sound source. The transducer is able to measure and generate acoustic waves in the ultrasound frequency band up to 1 MHz. The simulation considers numerical calculation of acoustic pressure distribution inside the tank in which acoustic source emits waves with frequency equal to 100 kHz. Verification analysis has confirmed consistency of the numerically calculated values with the measurement results.
Źródło:
Archives of Acoustics; 2012, 37, 1; 19-22
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of Partial Discharges in Cable Insulation and Cable Head Using Acoustic Method
Autorzy:
Ranachowski, Zbigniew
Wieczorek, Krzysztof
Ranachowski, Przemysław
Dębowski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2141672.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
partial discharges
medium voltage insulation
acoustic emission
Opis:
The article presents the application of Acoustic Emission (AE) method for detection and registration of partial discharges (PD) generated in medium voltage (MV) cable isolation and MV cable head. The insulation of the high voltage cable is made of a flexible material whose properties are characterised by a high coefficient of attenuation of the acoustic signals. For this reason, the AE method has not been used so far to detect PD in energetic cables. The subjects of the research were the MV cable and the standard T-type cable head. The cable contained defects which were the source of partial discharges. In case of cable head the PD were provoked by thin grounded electrode which was introduced into connector opening. The results of AE measurements are presented in the form of spectrograms. Acoustic Emission was evoked when the applied voltage level reached the value of 7.5 kV for the cable and 4 kV for the cable head. The authors used the acoustic instrumentation of their own design intended for future field use. Obtaining successful results of partial discharges measurements using the acoustic method in the cable insulation makes an original contribution of the presented work.
Źródło:
Archives of Acoustics; 2022, 47, 2; 259-265
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of a Phase Resolved Partial Discharge Pattern Analysis for Acoustic Emission Method in High Voltage Insulation Systems Diagnostics
Autorzy:
Kunicki, M.
Cichoń, A.
Powiązania:
https://bibliotekanauki.pl/articles/177912.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic emission
partial discharge
transformer diagnostics
insulation system
Opis:
An alternative method for analysis of acoustic emission (AE) signals generated by partial discharges (PD), based on a correlation between voltage phase run and AE pulses, so called phase resolved PD pattern (PRPD), is presented in the paper. PRPD pattern is a well-known analysis tool commonly used in such PD diagnostic methods as conventional electrical and UHF ones. Moreover, it yields various signal analysis abilities and allows a direct correlation indication between measurement results achieved using different methods. An original PRPD measurement methodology applied for AE method as well as some exemplary measurement results and further data analysis capabilities are presented in the paper. Also a comparative analysis of PRPD patterns achieved using various measurement methods and different PD source configurations have been investigated. All presented experiments were done under laboratory conditions using PD model sources immersed in the insulation oil. The main purpose of the presented research is to indicate an all-embracing analytical tool that yields an ability to direct comparison (qualitative as well as quantitative) of the AE measurement results with other commonly applied PD measurement methods. The presented results give a solid fundamental for further research work concerning a direct correlation method for AE and other described in the paper diagnostic techniques, mainly in order to continue PD phenomena analysis and assessment in real life high voltage apparatus insulation systems under normal onsite operation conditions.
Źródło:
Archives of Acoustics; 2018, 43, 2; 235-243
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Insulation of Dwellings Façades : the Case of Santiago de Chile
Autorzy:
Meza, Leonardo
Delannoy, Jaime
Marzzano, Antonio
Fuentes, Mauricio
Powiązania:
https://bibliotekanauki.pl/articles/176347.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound reduction index
construction quality
acoustic insulation
façade
Opis:
The increment in the number of automobiles and the densification of the city has increased noise pollution rates. In addition, the lack of regulation in Chile regarding the acoustic insulation of façades is a problem of a growing concern. The main objective of the present study was to obtain a model of the Sound Insulation of housing, façades, stratified in Santiago, Chile, based on constructive variables. It is expected to serve as a basis for one future regulation for acoustic façades of houses. In the present study, tests based on the international ISO 140-5 standard were carried out in situ. An estimation model of the Standardized Level Difference Dls;2m;nT;w + C, was obtained based on the opening/façade proportion, and the type of glass used for the windows.
Źródło:
Archives of Acoustics; 2019, 44, 1; 99-104
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Sound Transmission across a Floating Floor in a Residential Building by Using SEA
Autorzy:
Huang, Xianfeng
Lu, Yimin
Qu, Chen
Zhu, Chenhui
Powiązania:
https://bibliotekanauki.pl/articles/1953500.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound transmission
floating floor
impact noise
sound insulation
Opis:
For the purpose of reducing the impact noise transmission across floating floors in residential buildings, two main sound transmission paths in the floating floor structure are considered: the stud path and the cavity path. The sound transmission of each path is analysed separately: the sound transmission through the cavity and the stud are predicted by statistical energy analysis (SEA). Then, the sound insulation prediction model of the floating floor is established. There is reasonable agreement between the theoretical prediction and measurement, and the results show that a resilient layer with low stiffness can attenuate the sound bridge effect, resulting in higher impact noise insulation. Then, the influences of the floor covering, the resilient layer and the floor plate on the impact sound insulation are investigated to achieve the optimised structure of the floating floor based on the sound insulation.
Źródło:
Archives of Acoustics; 2021, 46, 1; 183-194
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of Sound Insulation Through Double-Panel Structure by Using Hybrid Local Resonator Array
Autorzy:
Ri, Kyong-Su
Kim, Myong-Jin
Son-U, Se-Hyon
Powiązania:
https://bibliotekanauki.pl/articles/31339917.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound insulation
local resonance
insertion loss
sonic crystal
Opis:
In this paper, we present one approach to improve the soundproofing performance of the double-panel structure (DPS) in the entire audible frequencies, in which two kinds of local resonances, the breathing-type resonance and the Helmholtz resonance, are combined. The thin ring resonator row and slit-type resonator (Helmholtz resonator) row are inserted between two panels of DPS together. Overlapping of the band gaps due to the individual resonances gives a wide and high band gap of sound transmission in the low frequency range. At the same time, the Bragg-type band gap is created by the structural periodicity of the scatterers in the high audible frequency range. In addition, the number of scatterer rows and the filling factor are investigated with regard to the sound insulation of DPS with sonic crystals (SCs). Consequently, the hybrid SC has the potential of increasing the soundproofing performance of DPS in the audible frequency range above 1 kHz by about 15 dB on average compared to DPS filled only with glass wool between two panels, while decreasing the total thickness and mass compared to the counterparts with the other type of local resonant sonic crystal.
Źródło:
Archives of Acoustics; 2023, 48, 1; 63-70
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability of the Acoustic Emission Signals Generated by Partial Discharges in Mineral Oil
Autorzy:
Kunicki, Michał
Powiązania:
https://bibliotekanauki.pl/articles/177772.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic emission
partial discharge
insulation system
measurements
signal processing
Opis:
The main purpose of the presented research is to investigate the partial discharge (PD) phenomenon variability under long-term AC voltage with particular consideration of the selected physical quantities changes while measured and registered by the acoustic emission method (AE). During the research a PD model source generating surface discharges is immersed in the brand new insulation mineral oil. Acoustic signals generated by the continuously occurred PDs within 168 hours are registered. Several qualitative and quantitative indicators are assigned to describe the PD variability in time. Furthermore, some longterm characteristics of the applied PD model source in mineral oil, are also presented according to acoustic signals emitted by the PD. Finally, various statistical tools are applied for the results analysis and presentation. Despite there are numerous contemporary research papers dealing with long-term PD analysis, such complementary and multiparametric approach has not been presented so far, regarding the presented research. According to the presented research from among all assigned indicators there are discriminated descriptors that could depend on PD long-term duration. On the grounds of the regression models analysis there are discovered trends that potentially allow to apply the results for modeling of the PD variability in time using the acoustic emission method. Subsequently such an approach may potentially support the development and extend the abilities of the diagnostic tools and maintenance policy in electrical power industry.
Źródło:
Archives of Acoustics; 2019, 44, 2; 339-348
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variable Sound Insulation Structure with MFC Elements
Autorzy:
Górski, P.
Kozupa, M.
Powiązania:
https://bibliotekanauki.pl/articles/177289.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound insulation
active noise reduction
macro fiber composite (MFC)
Opis:
Additional sound sources are used as actuators in the vast majority of active noise reduction systems. One of the possible opportunities to extend the field of applications of active noise reduction systems is using active structures of variable sound insulation. The paper presents an analysis of ways of reducing noise with a structure of variable sound insulation consisting of a metal plate, active elements (Macro Fiber Composite), and a control system. The paper presents results of acoustic radiation simulations and measurements of sound intensity generated by the structure under the influence of stimulation by an acoustic wave. Simulations of mechanical vibrations and acoustic radiation for the plate were performed with the finite element method and ANSYS software. Simulation results made it possible to select locations for gluing the active elements and sensors. Analyses of the sound pressure level in the space to which the plate is radiating made it possible to determine dominant frequencies in the characteristics and, as a result, indicate vibration modes that can be reduced. Sound intensity measurements were performed with a three-way probe of USP mini Microflown. Results of simulations and measurements show that it is possible to achieve an improvement of the insulating power of a metal plate by approx. 10 dB.
Źródło:
Archives of Acoustics; 2012, 37, 1; 115-120
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis on Acoustic Disturbance Signals Expected During Partial Discharge Measurements in Power Transformers
Autorzy:
Kunicki, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1953519.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic emission
partial discharge
insulation system
measurements
power transformers
Opis:
This paper presents comparative analysis of various acoustic signals expected during partial discharge (PD) measurements in operating power transformer. Main purpose of the paper is to yield relevant and reliable method to distinguish between various acoustic emission (AE) signals emitted by PD and other sources, with particular consideration of real-life results rather than laboratory simulations. Therefore, selected examples of real-life AE signals registered in seven different power transformers, under normal operation conditions, within few years are showed and analyzed. Five scenarios are investigated, which represent five types of AE sources: PD generated by artificial sources, and next four real-life sources (including PD in working transformer, oil flow, oil pumps and core). Several different signal processing methods are applied and compared in order to identify the PD signals. As a result, an energy patterns analysis based on the wavelet decomposition is found as the most reliable tool for identification of PD signals. The presented results may significantly support the process of interpretation of the PD measurement results, and may be used by field engineers as well as other researchers involved in PD analysis using AE method. Finally, observed properties also provide a solid basis for establishing or improving complete classification method based on the artificial intelligence algorithms.
Źródło:
Archives of Acoustics; 2020, 45, 4; 733-746
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving Sound Transmission Through Triple-Panel Structure Using Porous Material and Sonic Crystal
Autorzy:
Kim, Myong-Jin
Powiązania:
https://bibliotekanauki.pl/articles/177186.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound transmission loss
sonic crystal
triple-panel structure
sound insulation
Opis:
Main aim of this study is to combine the characteristics of the sonic crystal (SC) with acoustic panels and porous materials to improve the sound transmission loss (STL) through the triple-panel structure. SCs cause a bandgap centered around a certain frequency (Bragg’s frequency) due to generation of destructive interference. Initially, an analytical method is developed that extends the previous theory of double-panel structure to predict STL through a triple-panel structure. Finite element (FE) simulations are performer to obtain the STL through the triple-panel, which are validated with the analytical predictions. Various configurations are analyzed using the FE method based on the method of inserting the porous material and SCs between the panels to address the combined effect. STL through the triple-panel structure is compared with that through the double-panel structure having the same total weight and total thickness. It is found that the combined structure of the triple panel and the SC with glass wool as filler gives the best soundproof performance for the same external dimensions. For narrow air gaps, filing with glass wool is more advantageous than inserting one row of SC. In addition, the triple panel combined with a SC has better soundproofing than the two-panel counterparts.
Źródło:
Archives of Acoustics; 2019, 44, 3; 533-541
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using Clustering Methods for the Identification of Acoustic Emission Signals Generated by the Selected Form of Partial Discharge in Oil-Paper Insulation
Autorzy:
Borucki, S.
Łuczak, J.
Zmarzły, D.
Powiązania:
https://bibliotekanauki.pl/articles/177657.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic emission method
acoustic signals
partial discharges
insulation
power transformer
Opis:
The article presents the results concerning the use of clustering methods to identify signals of acoustic emission (AE) generated by partial discharge (PD) in oil-paper insulation. The conducted testing featured qualitative analysis of the following clustering methods: single linkage, complete linkage, average linkage, centroid linkage and Ward linkage. The purpose of the analysis was to search the tested series of AE signal measurements, deriving from three various PD forms, for elements of grouping (clusters), which are most similar to one another and maximally different than in other groups in terms of a specific feature or adopted criteria. Then, the conducted clustering was used as a basis for attempting to assess the effectiveness of identification of particular PD forms that modelled exemplary defects of the power transformer’s oil-paper insulation system. The relevant analyses and simulations were conducted using the Matlab estimation environment and the clustering procedures available in it. The conducted tests featured analyses of the results of the series of measurements of acoustic emissions generated by the basic PD forms, which were obtained in laboratory conditions using spark gap systems that modelled the defects of the power transformer’s oil-paper insulation.
Źródło:
Archives of Acoustics; 2018, 43, 2; 207-215
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Optimization of Underwater Lower-Frequency Sound Insulation for Locally Resonant Sonic Material Using Genetic Algorithm
Autorzy:
Yuan, Bo
Chen, Yong
Tan, Bilian
Li, Bo
Powiązania:
https://bibliotekanauki.pl/articles/177461.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
underwater acoustic
sound insulation
local resonance
statistical optimization
global optimum
Opis:
The locally resonant sonic material (LRSM) is an artificial metamaterial that can block underwater sound. The low-frequency insulation performance of LRSM can be enhanced by coupling local resonance and Bragg scattering effects. However, such method is hard to be experimentally proven as the Best optimizing method. Hence, this paper proposes a statistical optimization method, which first finds a group of optimal solutions of an object function by utilizing genetic algorithm multiple times, and then analyzes the distribution of the fitness and the Euclidean distance of the obtained solutions, in order to verify whether the result is the global optimum. By using this method, we obtain the global optimal solution of the low-frequency insulation of LRSM. By varying parameters of the optimum, it can be found that the optimized insulation performance of the LRSM is contributed by the coupling of local resonance with Bragg scattering effect, as well as a distinct impedance mismatch between the matrix of LRSM and the surrounding water. This indicates coupling different effects with impedance mismatches is the Best method to enhance the low-frequency insulation performance of LRSM.
Źródło:
Archives of Acoustics; 2019, 44, 2; 365-374
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Acoustic Effect of Windows Installed in a Wood Frame Façade
Autorzy:
Nurzyński, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/31339867.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound insulation
lightweight frame building
prefabricated façad
windows
protection against noise
Opis:
The acoustic effect of windows installed in a prefabricated wood frame façade was considered. Windows inserted into a lightweight wall modify its structural scheme. The research aimed to investigate the possible interaction of the façade’s main components and their actual contribution to the total sound insulation. The principal research question involved the prediction of the acoustic performance of the complete prefabricated panel from the performance of its basic elements, an opaque part and windows. As the frequency-dependent characteristics of the elements differ substantially, the use of single number values for prediction and accuracy was of particular interest. The study is based on laboratory measurements. Initially, two full-scale samples of an opaque wall and four windows were tested separately. Then, several variants of the façade consisting of various combinations of these elements were examined. The results of measurements were juxtaposed and compared with calculated values. The frequency-dependent experimental results were fairly consistent with calculations. The estimations based on single number quantities were also in good agreement with measurements. Thus, it may be concluded that the façade elements did not interact significantly, and the single number calculations give reliable results that can be used in practice.
Źródło:
Archives of Acoustics; 2023, 48, 3; 183-190
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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