PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 17

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  poziom mocy akustycznej
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Sound power level estimation - choice of the prior distribution
Stępień Bartłomiej
Vibrations in Physical Systems
|
2023
|
Vol. 34, nr 1
art. no. 2023110
EN
Bayesian inference is one of the methods used to determine the sound power level of sound sources. This method requires knowledge of two probability distributions. The first is the sampling density, while the second is the prior distribution. In this study, the effect of the prior distribution on the sound power level estimation results was investigated. For this purpose, three prior distributions were used: 1) a normal distribution, 2) a distribution determined using the kernel density estimator, 3) a uniform distribution. The sound power level results determined by the engineering method were used to illustrate the proposed solutions and carry out the analysis. The results of the experiment were compared with the results of the sound power level determined using the precision method in the hemi-anechoic room according to ISO 3745:2012. The statistical inference has been carried out based on results of non-parametric statistical tests at the significance level α = 0.05.
2
Content available Bootstrap estimation of sound power level determined by the survey method
Stępień Bartłomiej
Vibrations in Physical Systems
|
2023
|
Vol. 34, nr 2
art. no. 2023210
EN
The possibility of using the bootstrap method to determine the sound power level for the survey method was presented in this paper. Minimum values of the bootstrap algorithm input parameters have been determined for the estimation of sound power level. Two independent simulation experiments have been performed for that purpose. The first experiment served to determine the impact of the original random sample size, and the second to determine the impact of a number of the bootstrap replications on the accuracy of estimation of sound power level. The inference has been carried out based on the results of non-parametric statistical tests at significance level α = 0.05. The statistical analysis has shown that the minimum size of the original random sample n used to estimate the value of sound power level should be 4 elements for the survey method. The minimum number of bootstrap replications necessary for the estimation of sound power level should be B = 5100. The study on the usefulness and effectiveness of the bootstrap method in the determination of sound power level in real-life situation was carried out with the use of data representing actual results. The data used to illustrate the proposed solutions and carry out the analysis were the results of sound power levels of reference sound power source B&K 4205 were used.
3
Określanie poziomów mocy akustycznej urządzeń w Centralnym Ośrodku Chłodnictwa „COCH" w Krakowie. Cz. 1, Uwarunkowania techniczne oraz wymagania wynikające z przepisów, dotyczące urządzeń chłodniczych oraz pomp ciepła
Kopińska Anna, Gratkowski MIłosz
Chłodnictwo i Klimatyzacja
|
2021
|
nr 10
52--54, 56
PL
Rozwijający sią rynek urządzeń chłodniczych i pomp ciepła, rosnące wymagania klientów oraz nowe regulacje, sprawiają, iż uwaga producentów oraz odbiorców skupia sią na emitowanym przez urządzenia hałasie. Świadczy o tym między innymi wprowadzenie w marcu 2021 roku do etykiety energetycznej urządzeń chłodniczych oznaczenia klasy emisji hałasu. Wdrożenie takiego systemu oznakowania pozwala uniknąć nieporozumień związanych z wartościami parametrów akustycznych. Zharmonizowanie wytycznych daje możliwość swobodnej dystrybucji urządzeń, a także ochrony środowiska naturalnego i zdrowia użytkowników.
4
Content available Determination of the sound power level of modular machines with cyclic operation mode - case study
Jakubek Bartosz, Barczewski Roman
Vibrations in Physical Systems
|
2020
|
Vol. 31, nr 1
art. no. 2020101
EN
The sound power level as a parameter characterizing a sound source, as opposed to the sound pressure level, should theoretically not depend on the place of measurement and distance from the source. Therefore, it is often used as a basis for comparing machines and equipment in terms of noise emissions. Manufacturers usually specify this parameter in the technical documentation or on the equipment. The sound power level is also a necessary parameter for modelling the natural and working environment in terms of acoustics. The standards for methods of determining the sound power level define three classes of accuracy depending on the method and environment of measurement. The paper outlines the problems associated with determining the sound power level of non-standard machines in situ. The case study concerns a machine, a modular SRP (shelf ready packaging) production system that can be part of an extensive production line. Specific for this type of machine is the coexistence of many local sources generating sound of different nature, cyclic mode of operation and the possibility to set different capacity.
5
Content available The impact of the damper blade position on the generated noise and pressure losses in plenum box with swirl diffusers
Wójciak Kamil, Gaj Patryk, Kopania Joanna, Bogusławski Grzegorz
Vibrations in Physical Systems
|
2019
|
Vol. 30, nr 1
art. no. 2019103
EN
The article presents the effect of setting the throttle in the plenum box with swirl diffuser on the generated noise and the pressure losses. The sound power levels of the source was determined using the precision method in the reverberation room in accordance with the PN-EN ISO 3741:2011 standard. The examination was carried out for damper blade position set vertically and horizontally for full opening and at a 45 degree angle in both directions. In order to confirm the universality of the conducted experiment, the tests were carried out for two different face swirl diffuser with different shapes of air control blades and holes in the plate and for different flow rates. The multi-criteria optimization methods were used to select the best throttle position.
6
Content available Determination of sound power level by using a microphone array and conventional methods
Bogusławski Grzegorz, Kopania Joanna Maria, Gaj Patryk, Wójciak Kamil
Vibrations in Physical Systems
|
2019
|
Vol. 30, nr 1
art. no. 2019139
EN
Sound power is measured to make objective comparisons between the same type of products, but also because legislation requires it. To release a new product, it is often compulsory to certify it according to International Organization for Standardization (ISO) standards, and also with national and local regulations. Determining of sound power is not a straightforward process. Sound power can be determined through the measurement of sound pressure (series 3740 methods) or sound intensity (series 9614 methods). Selecting one of the above methods depends on the purpose of the test, as well as the available equipment, desired grade of accuracy, background noise level or the test environment. Nowadays the additional methods, such as microphone arrays are used to located of the noise source and determined of pressure sound level. But the results obtained with acoustic cameras cannot be, for now, used for legislative purposes (are not ISO compliant). In this work the differences in the determination of sound power level by using conventional ISO methods and microphone arrays are determined. The system composed of a loudspeaker and a fan were used as a sound source of the noise. Sound power levels according to ISO 3746 and ISO 9614-1 were determined and were compared with the developed method by using microphone arrays techniques.
7
Content available The noise of biomedical devices for domiciliary use on the example of a nebulizer
Jakubek B., Rukat W., Grochalski K.
Vibrations in Physical Systems
|
2018
|
Vol. 29
art. no. 2018017
EN
Widely available and inexpensive biomedical devices for domiciliary use may emit noise. Nebulizers are one of them. They allow taking drugs in the form of vapours thanks to vaporization under reduced pressure using an ejector (vacuum generator). The sources of noise in a nebulizer are an air compressor and a vaporizing tip. The presence of two sources with a different noise character and unfixed spatial orientation allows to classify a nebulizer as a device with extensive sound sources (DESS). The article presents the results of acoustic measurements of the nebulizer and its components. Differences in the nature of components’ noise were found and their estimates were compared. Noise hazards for the device’s user were determined and the premises for the noise parameterization of devices of this type were specified.
8
Content available The noise emitted by a vacuum cleaner treated as a device with extensive sound sources
Rukat W., Jakubek B., Madej A.
Vibrations in Physical Systems
|
2018
|
Vol. 29
art. no. 2018015
EN
Vacuum cleaners can be found in almost every household. They are one of the most intense noise sources there. Noise generated by vacuum cleaners is partially of mechanical, electrical and aerodynamic origin. A suction unit is the source of mechanical and electromagnetic noise. A suction nozzle or a cleaning head as well as a flexible hose that connects the components are sources of aerodynamic noise. The noise of the suction unit depends on the load and the technical condition of the motor. The noise of the nozzle and the hose depend on the flow capacity, presence of solid particles and the type of cleaned surface. The article presents a comparison of acoustic parameters of a vacuum cleaner working on various surfaces. In addition, the noise generated by the vacuum cleaner was compared according to the standard noise testing procedure and according to the definition of devices with extensive sound sources.
9
Content available Emisje hałasu w górnictwie nafty i gazu – wiertnie
Zaleska-Bartosz J., Niemczewska J.
Nafta-Gaz
|
2018
|
R. 74, nr 4
319--328
PL
W artykule przedstawiono wyniki pomiarów hałasu środowiskowego towarzyszącego pracy urządzeń eksploatowanych na różnych etapach wiercenia otworu. Uzyskane wyniki posłużyły autorom do przeprowadzenia symulacji w celu określenia przybliżonych poziomów mocy akustycznych urządzeń, których równoczesna praca na wiertni była źródłem hałasu na zmierzonym poziomie.
EN
The article presents the results of environmental noise measurements accompanying the work of equipment operated at different stages of drilling. The obtained results were used by the authors to perform simulations aimed at estimating the approximate sound power levels of devices, for which the simultaneous work on the drilling was the source of noise at the measured level.
10
Content available Emisje hałasu w górnictwie nafty i gazu – kopalnie
Zaleska-Bartosz J., Kołodziejak G.
Nafta-Gaz
|
2018
|
R. 74, nr 5
380--385
PL
W artykule przedstawiono wyniki pomiarów hałasu środowiskowego towarzyszącego pracy urządzeń eksploatowanych w obiektach technologicznych kopalń gazu ziemnego i ropy naftowej oraz wyniki pomiarów ciśnienia akustycznego przeprowadzonych w celu wyznaczenia poziomów mocy akustycznych urządzeń stanowiących główne źródła hałasu w kopalniach. Wyznaczone poziomy mocy akustycznych wykorzystano do przeprowadzenia symulacji rozprzestrzeniania się hałasu w środowisku. Wartości poziomów emisji hałasu uzyskane na drodze symulacji porównano z wartościami pochodzącymi z bezpośrednich pomiarów hałasu środowiskowego, w punktach kontrolnych odpowiadających punktom pomiarowym.
EN
The article presents the results of environmental noise measurements, accompanying the work of equipment operated in technological facilities of natural oil and gas mines and the results of sound pressure level measurements, conducted to determine the sound power levels of the devices that are the predominant sources of noise in the mines.
11
Content available Ocena uciążliwości akustycznej stacji elektroenergetycznych najwyższych napięć
Jaworski M., Szuba M.
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
|
2017
|
Nr 56
33--37
PL
W referacie przedstawiono główne źródła hałasu występujące na terenie stacji elektroenergetycznych. Zaprezentowano wyniki pomiarów poziomu mocy akustycznej jednostek transformatorowych pracujących na wybranych stacjach elektroenergetycznych, w tym zależności poziomu mocy akustycznej od ilości pracujących układów wentylatorowych. Omówiono trudności w poprawnym wykonywaniu pomiarów ciśnienia akustycznego w otoczeniu transformatorów oraz problemy w dotrzymaniu dopuszczalnych poziomów dźwięku na terenach chronionych akustycznie w przypadku rozbudowy stacji elektroenergetycznych. W referacie poruszono także problem szacowania hałasu skumulowanego.
EN
This paper presents the main sources of noise generated by high voltage power stations and the results of measurements of the sound power level of transformer units at selected power stations. The impact on the sound power level on the number of working fan systems is also presented. Difficulties in sound pressure measurements in transformer environment and difficulties in meeting acceptable sound levels in acoustically protected areas in the case of extension of power substations are discussed. The paper also demonstrated of some problems with estimating cumulative noise. The results of measurements in the environment of an autotransformer operating at the high voltage power stations showed that the operating conditions of individual sections of the autotransformer fan have no significant effect on the calculated acoustic power levels of the autotransformer. The main source of noise in the autotransformer is not the cooling fans but the sound produced in the core of the transformers and the sound accompanying the electromagnetic forces (magnetostriction).
12
Content available Determination of acoustic parameters of devices with extensive sound sources
Jakubek B., Barczewski R.
Vibrations in Physical Systems
|
2016
|
Vol. 27
129--134
EN
In most cases, while the sound power level of machines and devices is determined, it is assumed that tested objects are sound sources which can fit in a so-called reference box. Such an approach takes into account the influence of local sources. Although it does not allow their localization, separate noise measurement and evaluation. There are devices which have two or more relevant sound sources. In this paper this type of devices has been defined as devices with extensive sound sources (DESS). The tested device is a functional unit but its local sound sources are distant from each other. The results showed that determining the sound power level only is not sufficient for proper parameterization of noise emitted by DESS.
13
Content available remote Acoustic properties of small wind turbines
Szulczyk J., Cempel C.
Vibrations in Physical Systems
|
2012
|
Vol. 25
405--410
EN
The study of vibroacoustic properties of small wind turbines with a vertical axis laboratory test conditions used in the form of an anechoic chamber in the Acoustics Laboratory, Institute of Energy, Department of Heat in. Anechoic chamber design allowed the installation of a duct through which the airflow is adjusted by means of a centrifugal fan mounted at the inlet of the waveguide. The paper presents the identification of the acoustic parameters of acoustic small wind turbines with a vertical axis comprising: a) determination of sound power levels for different classes of frequency characteristics and test wind turbines work b) identification of the components of the spectrum frequency - amplitude associated mainly with turbine speeds and frequencies of their own, such as duct The result of research was to obtain input data to define a more dedicated to the identification of measurement noise and vibration characteristics of wind turbines such as the efficiency of vibroacoustic, cepstrum analysis or dimensional analysis.
14
Emisja hałasu maszyn - wymagania dyrektywy 42/2006/WE
Mikulski W.
Bezpieczeństwo Przemysłowe
|
2008
|
T. 2
53-57
PL
Przedstawiony niżej tekst podaje metodę, zaimplementowaną w programie PRO-M, której zastosowanie umożliwia spełnienie wymagań dotyczących emisji hałasu maszyn, określonych w dyrektywie UE 42/2006/WE. Obowiązki te dotyczą ograniczenia ryzyka wynikającego z emisji hałasu maszyn, do najniższego możliwego do osiągnięcia metodami technicznymi poziomu oraz obowiązek deklarowania emisji hałasu maszyn przez podanie wie/kości charakteryzujących tą emisję.
EN
In this article the procedure, implemented in program PRO-M, is presented. The aim of this procedure is to meet the requirements of European Union directive 42/2006/WE for machinery noise emission. The requirements are related to reducing occupational risk from machinery noise exposure to the lowest possible level and to the obligatory declaration of machinery noise emission level using the appropriate values.
15
Poziom ciśnienia a poziom mocy akustycznej w systemach wentylacji i klimatyzacji
Adamski B.
Chłodnictwo i Klimatyzacja
|
2007
|
nr 4
12-17
PL
W niniejszym artykule przedstawiono podstawowe zagadnienia i zależności empiryczne związane z akustyką wyżej wymienionych źródeł hałasu, wykorzystywanych w technice chłodniczej i klimatyzacyjnej.
16
Content available Niepewność wyznaczania poziomów mocy akustycznej źródeł hałasu
Mikulski W., Tadzik P.
Bezpieczeństwo Pracy : nauka i praktyka
|
2001
|
nr 6
2-5
PL
Przedstawiono wyniki badań poziomu mocy akustycznej wzorcowego źródła dźwięku w różnych warunkach pomiarowych przy zastosowaniu metody technicznej o klasie dokładności 2 i metody orientacyjnej o klasie dokładności 3, w określonych normach PN-EN ISO 3744 oraz PN-EN ISO 3746. Porównano wartości odchylenia standardowego odtwarzalności poziomów mocy akustycznej uzyskanych w badaniach z podanymi w wymienionych normach.
EN
This article presents the results of sound power level determination of a reference sound source under different measurement conditions using an engineering method, precision class 2 and a survey method precision class 3 as specified in PN EN ISO 3744 and PN-EN ISO 3746. Standard deviations of the reproducibility of sound power levels determined according to the above-mentioned standards were compared.
17
Content available remote Hałas maszyn – znormalizowane metody wyznaczania poziomu mocy akustycznej. Cz.1
Augustyńska D., Pleban D., Mikulski W.
Bezpieczeństwo Pracy : nauka i praktyka
|
2000
|
nr 2
7-13
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.