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    Wyświetlanie 1-25 z 25
    Tytuł:
    Modeling and Designing Acoustical Conditions of the Interior – Case Study
    Autorzy:
    Kostek, B.
    Laskowski, S.
    Mizgier, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/176652.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic field analysis
    acoustic field modeling
    acoustic conditions measurements
    acoustic conditions analysis
    sound reinforcement system design
    Opis:
    The primary aim of this research study was to model acoustic conditions of the Courtyard of the Gdańsk University of Technology Main Building, and then to design a sound reinforcement system for this interior. First, results of measurements of the parameters of the acoustic field are presented. Then, the comparison between measured and predicted values using the ODEON program is shown. Collected data indicate a long reverberation time which results in poor speech intelligibility. Then, a thorough analysis is perform to improve the acoustic properties of the model of the interior investigated. On the basis of the improved acoustic model two options of a sound reinforcement system for this interior are proposed, and then analyzed. After applying sound absorbing material it was noted that the predicted speech intelligibility increased from bad/poor rating to good category.
    Źródło:
    Archives of Acoustics; 2016, 41, 3; 473-484
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical modeling of transient acoustic field using finite element method
    Autorzy:
    Koudela, L.
    Jansa, J.
    Karban, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/377945.pdf
    Data publikacji:
    2013
    Wydawca:
    Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
    Tematy:
    acoustic field
    finite element method
    acoustic wave
    Opis:
    Numerical solution of acoustic wave equation in the time domain is performed. The appropriate mathematical model is described by the partial differential wave equation supplemented with appropriate boundary conditions. The goal is to obtain the time evolution of the distribution of acoustic pressure, which can serve as the basis for the solution of various subsequent problems. The paper discusses the results of the numerical analysis of a semicircular acoustic diffuser in a free field, realized by a fully adaptive higher-order finite element method implemented in our own codes Agros2D and Hermes. The results are compared with the data obtained by the commercial code Comsol Multiphysics.
    Źródło:
    Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 73; 155-160
    1897-0737
    Pojawia się w:
    Poznan University of Technology Academic Journals. Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The method of mapping of acoustic field, emitted by sources of sound in the environment, with implementation of the MEMS IMU unit and laser devices
    Autorzy:
    Kompała, J.
    Motyka, Z.
    Szade, A.
    Świder, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/114389.pdf
    Data publikacji:
    2015
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    acoustic field
    inertial unit
    laser device
    Opis:
    During the course of the research, a methodology of measurement of sources of noise was developed, along with measurement models and measurement sets. The latter were equipped with microphones, acoustic pressure level meters, devices determining spatial orientation of the measurement (laser rangefinder, inertial measurement unit 3D IMU) and software processing the data, obtained including final spatial mapping of the acoustic field. The system has been successfully tried in large indoor areas.
    Źródło:
    Measurement Automation Monitoring; 2015, 61, 3; 68-71
    2450-2855
    Pojawia się w:
    Measurement Automation Monitoring
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wpływ oprzyrządowania pomiarowego na rozkład pola akustycznego
    An influence of the measuring instruments on the acoustic field distribution
    Autorzy:
    Olszewski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/250988.pdf
    Data publikacji:
    2013
    Wydawca:
    Instytut Naukowo-Wydawniczy TTS
    Tematy:
    pole akustyczne
    pomiary akustyczne
    acoustic field
    acoustic measurement
    Opis:
    Artykuł dotyczy badań modelowych wpływu oprzyrządowania pomiarowego na pole akustyczne w którym się znajdują. Przedstawiono wyniki dla dwóch obiektów różniących się kształtem, które są wymieniane jako możliwe do wykorzystania w charakterze urządzenia pozwalającego przemieszczać elementy toru pomiarowego.
    The paper concerns a model based research of an impact of a measurement equipment on the acoustic field it is located in. The results for the two objects that differ in shape, and both are possible to use as a device allowing to move the measurement path elements, are presented.
    Źródło:
    TTS Technika Transportu Szynowego; 2013, 10; 1117-1124, CD
    1232-3829
    2543-5728
    Pojawia się w:
    TTS Technika Transportu Szynowego
    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 Acoustic Field Distribution Inside the Ultrasonic Ring Array
    Autorzy:
    Staszewski, W.
    Gudra, T.
    Opieliński, K. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/177105.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ultrasound transmission tomography
    acoustic field
    ultrasonic multi-element array
    Opis:
    This paper presents and analyses the results of a simulation of the acoustic field distribution in sectors of a 1024-element ring array, intended for the diagnosis of female breast tissue with the use of ultrasonic tomography. The array was tested for the possibility to equip an ultrasonic tomograph with an additional modality - conventional ultrasonic imaging with the use of individual fragments (sections) of the ring array. To determine the acoustic field for sectors of the ring array with a varying number of activated ultrasonic transducers, a combined sum of all acoustic fields created by each elementary transducer was calculated. By the use of MATLAB software, a unique algorithm was developed, for a numerical determination of the distribution of pressure of an ultrasonic wave on any surface or area of the medium generated by the concave curvilinear structure of rectangular ultrasound transducers with a geometric focus of the beam. The analysis of the obtained results of the acoustic field distribution inside the ultrasonic ring array used in tomography allows to conclude that the optimal number of transducers in a sector enabling to obtain ultrasound images using linear echographic scanning is 32 ≤ n ≤ 128, taking into account that due to an increased temporal resolution of ultrasonic imaging, this number should be as low as possible.
    Źródło:
    Archives of Acoustics; 2018, 43, 3; 455-463
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modeling of acoustic field for a parametric focusing source using the spheroidal beam equation
    Autorzy:
    Yu, L.
    Li, J.
    Shi, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/258564.pdf
    Data publikacji:
    2015
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    parametric focusing source
    difference frequency wave
    SBE
    acoustic field
    Opis:
    A theoretical model of acoustic field for a parametric focusing source on concave spherical surface is proposed. In this model, the source boundary conditions of the Spheroidal Beam Equation (SBE) for difference frequency wave excitation were studied. Propagation curves and beam patterns for difference frequency component of the acoustic field are compared with those obtained for Khokhlov-Zabolotskaya-Kuznetsov (KZK) model. The results demonstrate that the focused parametric model of SBE is good valid for a large aperture angle in the strongly focused acoustic field. It is also investigated that high directivity and good focal ability with the decreasing of downshift ratio and the increasing of half-aperture angle for the focused parametric model of SBE.
    Źródło:
    Polish Maritime Research; 2015, S 1; 43-47
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Effect of Dynamic Beam Deflection and Focus Shift on the Acoustic Field Distribution Inside the Ultrasonic Ring Array
    Autorzy:
    Staszewski, Wiktor
    Gudra, Tadeusz
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176553.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    ultrasonic ring array
    acoustic field distribution
    ultrasonic beam focusing
    ultrasound tomography
    Opis:
    This paper presents the results of acoustic field distribution simulations for the 1024-element ultrasonic ring array intended for the diagnosis of female breast tissue with the use of ultrasound tomography. For the purpose of analysing data, all acoustic fields created by each elementary transducer were combined. The natural position of the focus inside the ultrasonic ring array was changed by altering activation time of individual transducers in sectors consisting of 32, 64, and 128 ultrasonic transducers. Manipulating the position of the focus inside the array will allow to concentrate the ultrasonic beam in a chosen location in the interior space of the ring array. The goal of this research is to receive the best possible quality of images of cross-sections of the female breast. The study also analysed the influence of the acoustic field distribution on the inclination of the beam. The results will enable to choose an optimal focus and an optimal number of activated transducers.
    Źródło:
    Archives of Acoustics; 2019, 44, 4; 625-636
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Use of Acoustic Vectors Decomposition of Sound Fields to Vibroacoustic Protection on Ships
    Autorzy:
    Weyna, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/177564.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic vectors field
    sound intensity
    ship acoustics
    Opis:
    In this paper, numerous examples will be illustrated as principles of applying the sound intensity measurements to practical problems at the noise abatement on ships and offshore constructions. The paper presents the results of transmission loss measurements together with flanking transmission for ship bulkheads and partitions with doors and windows. Investigations carried out with sound intensity measurement techniques will be compared against those made by classical methods. Finally for a few examples, the graphic presentation of spatial distribution of sound intensity vectors risen close to vibrating ship cabin partitions and inside the cabin will be shown in 2D and 3D graphical form. As a result, a two-dimensional acoustic wave flow map of time-averaged active intensity vectors propagated along curved streamlines and a vector perpendicular to measured plane are graphically illustrated. The technique of acoustic vectors decomposition of sound fields described, can enrich the knowledge of the mechanism of acoustic energy flux through ship partitions.
    Źródło:
    Archives of Acoustics; 2017, 42, 2; 207-212
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical modeling of Gauss monocycle pulse in transient acoustic field
    Autorzy:
    Koudela, L.
    Jansa, J.
    Karban, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/97307.pdf
    Data publikacji:
    2013
    Wydawca:
    Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
    Tematy:
    Gauss monocycle pulse
    acoustic transient field
    finite element method
    Opis:
    Numerical solution of acoustic wave equation in the time domain is performed. The mathematical model is described by the partial differential wave equation supplemented with appropriate boundary conditions. The goal is to obtain the time evolution of the distribution of acoustic pressure, which can serve as the basis for the solution of various subsequent problems. The paper discusses the results of the numerical analysis of the Gauss monocycle pulse that proceeds from the signal source and incident on the semi-circular acoustic diffuser in a free field, realized by a fully adaptive higherorder finite element method implemented in codes Agros2D and Hermes developed by the hp-FEM group. Selected results of the computations are compared with the data obtained by the commercial code COMSOL Multiphysics.
    Źródło:
    Computer Applications in Electrical Engineering; 2013, 11; 141-147
    1508-4248
    Pojawia się w:
    Computer Applications in Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analiza własności akustycznych pomieszczenia w zależności od kształtu sufitu
    Analysis of acoustic properties of room depending on the shape of ceiling
    Autorzy:
    Jabłoński, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/362605.pdf
    Data publikacji:
    2010
    Wydawca:
    Instytut Fizyki Budowli Katarzyna i Piotr Klemm
    Tematy:
    parametry akustyczne
    ocena akustyczna pomieszczeń
    komputerowy model pola akustycznego
    acoustic parameters
    estimate of acoustic accommodation
    computer model of acoustic field
    Opis:
    W pracy przedstawiono porównanie własności akustycznych pomieszczenia dla różnego rodzaju konstrukcji sufitu. Wykorzystano parametry związane ze stosunkiem energii (C80), przestrzenne (LF), określające zrozumiałość mowy (STI) oraz spadek energii w przestrzeni (DL2)
    This paper presents a comparison of acoustic properties of room for different types of ceiling construction. We used parameters related to energy ratio (C80), spatial (LF), indicating the speech intelligibility (STI) and a spatial decay (DL2).
    Źródło:
    Fizyka Budowli w Teorii i Praktyce; 2010, T. 5, nr 3, 3; 13-16
    1734-4891
    Pojawia się w:
    Fizyka Budowli w Teorii i Praktyce
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Testing the Acoustic Silencers
    Autorzy:
    Pierchała, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/176514.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    silencers
    aerodynamic noise
    noise reduction
    ventilation systems
    numerical tests
    acoustic field
    sound absorbing cassettes
    dispersing component
    Opis:
    Problems associated with designing silencers are presented. Results of direct tests of silencers for cooperation with systems of axial fans, as well as results of numerical tests of a two stage acoustic silencer, are given. The numerical tests enabled determining the distribution of acoustic field inside the silencer and in the surrounding area. In those tests A sound insertion losses for different variants of installation inside the silencer, as well as for two different types of absorbing material used to fill the silencer walls, were determined. Impact of design features of silencers on effectiveness of noise reduction is described. Also, a technical sketch of a universal silencer with significant noise reduction (DipS = 39:1 dB) which can be successfully used in many ventilation systems is presented.
    Źródło:
    Archives of Acoustics; 2018, 43, 2; 313-321
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Badania pól elektromagnetycznych i hałasu na terenie biogazowni rolniczej
    Study of electromagnetic fields and noise in the area of agricultural biogas plant
    Autorzy:
    Mazurek, P. A.
    Pawłat, J.
    Wraga, S.
    Wojtacha, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/401423.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    biogazownia
    bioelektrownia
    natężenia pól elektrycznych i magnetycznych
    natężenia pól akustycznych
    bioenergy
    biogas plant
    electric and magnetic field strength
    acoustic field strength
    Opis:
    W pracy przedstawiono wartości pól elektromagnetycznych i hałasu wprowadzanych do środowiska na podstawie wyników pomiarów przeprowadzonych na obszarze zakładu biogazowi rolniczej o mocy 0,999MW zlokalizowanej w Piaskach. Wartości te odniesiono do obowiązujących w kraju norm dotyczących ekspozycji na pola elektryczne i magnetyczne oraz hałas. Nie stwierdzono przekroczenia ekspozycji dopuszczalnych w obszarach stałego pobytu ludzi.
    Electro-magnetic and acoustic fields were analysed at the bioenergy and biogas production plant of 0.999 MW operational power, localized in Piaski. Measured values were compared with valid national norms and did not exceed limiting values in zones of people’s permanent residence.
    Źródło:
    Inżynieria Ekologiczna; 2016, 50; 63-70
    2081-139X
    2392-0629
    Pojawia się w:
    Inżynieria Ekologiczna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zastosowanie radialnych funkcji bazowych do analizy pola akustycznego wnętrz pojazdów
    Analysis of acoustic field in vehicle interior with Radial Based Functions
    Autorzy:
    Majkut, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/316351.pdf
    Data publikacji:
    2016
    Wydawca:
    Instytut Naukowo-Wydawniczy "SPATIUM"
    Tematy:
    metoda bezsiatkowa
    pole akustyczne
    metoda elementów skończonych (MES)
    radialne funkcje bazowe
    meshless method
    acoustic field
    finite element analysis
    radial base functions
    Opis:
    W artykule opisano możliwości zastosowania jednej z tzw. metod bezsiatkowych do analizy pola akustycznego wnętrza pojazdu. Do analizy wybrano metodę kolokacyjną z bazą globalnych funkcji radialnych. W kolejnych punktach pracy opisano wykorzystywaną metodę analizy i jej zastosowanie do wyznaczenia częstości drgań własnych i charakterystyk amplitudowo-częstotliwościowych wnętrza przykładowego pojazdu. Charakterystyki wyznaczono w dwóch układach źródła: jedno źródło zlokalizowane na środku przedniej części pojazdu (układ siso) i dwa źródła umieszczone po bokach pojazdu (układ miso). Wartości częstości własnych porównano z analizą Metodą Elementów Skończonych.
    The work concerns the in acoustics of an vehicle interior with the Radial Based Functions. The collocation method was used for determination eigenvalues and frequency response functions of the car interior. All eigenvalues were compared with Finite Element Analysis results. All results indicate that using of multiquadric (MQ) RBF provide a results with very high accuracy in comparison to numerical results in acoustic analysis of 3D close domain.
    Źródło:
    Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 12; 1183-1187
    1509-5878
    2450-7725
    Pojawia się w:
    Autobusy : technika, eksploatacja, systemy transportowe
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of dynamic focusing of the beam on the acoustic field distribution inside the ultrasonic ring array
    Autorzy:
    Staszewski, Wiktor
    Gudra, Tadeusz
    Powiązania:
    https://bibliotekanauki.pl/articles/128006.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    ultrasonic ring array
    acoustic field distribution
    dynamic focusing of ultrasonic beam
    pierścieniowa głowica ultradźwiękowa
    rozkład pola akustycznego
    dynamiczne ogniskowanie wiązki ultradźwiękowej
    Opis:
    This paper presents the analysis of readings acquired from the ultrasonic ring array used in tomography for the diagnosis of female breast tissue. In addition, this paper also presents the results for the acoustic field distribution simulation, acquired through a method of summing up all acoustic fields generated by each of the elementary transducers of the ring array. The change in acoustic field pressure level when changing activation frequency (2 MHz, 3MHz, 4MHz) of the elementary ultrasonic transducers for the sector consisting of 32 and 64 ultrasonic transducers was studied. By changing the time of activation of individual transducers, a change in the natural position of the focus inside the ultrasonic ring array was observed. For the sector consisting of 32 ultrasonic transducers the relation between the echo coming from the wires of the wire pattern and the level of noise and distortion on the ultrasonographic image for different locations of the focus of the central transducers was studied. The results were compared with the simulations of the acoustic field, which were conducted using MATLAB software. This research is the continuation of studies [13, 14] aimed at choosing the optimal focus and number of transducers in ultrasonic ring array with the goal of receiving the best possible quality of images of cross-sections of the female breast.
    Źródło:
    Vibrations in Physical Systems; 2019, 30, 1; 1-8
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ocena wpływu modyfikacji kształtu krawędzi górnej ekranu akustycznego na rozkład pola akustycznego po stronie odbiorcy
    Evaluation of influence shape modification of sound barrier upper edge on the acoustic field distribution by receiver side
    Autorzy:
    Dulak, L
    Marchacz, M
    Nowoświat, A
    Olechowska, M
    Żuchowski, R
    Powiązania:
    https://bibliotekanauki.pl/articles/362988.pdf
    Data publikacji:
    2011
    Wydawca:
    Instytut Fizyki Budowli Katarzyna i Piotr Klemm
    Tematy:
    ekrany akustyczne
    kształt górnej krawędzi
    nakładka krawędziowa
    dyfrakcja
    rozkład pola akustycznego
    sound barriers
    upper edge shape
    edge cover
    diffraction
    acoustic field distribution
    Opis:
    Artykuł przedstawia badania modelowe w komorze bezechowej ekranu akustycznego w skali 1:1 wraz z nakładka krawędziową o pewnym kształcie. Uzyskane wyniki są podstawą do oceny jakościowej i ilościowej zastosowanego rozwiązania w kontekście zmiany pola akustycznego za ekranem po stronie odbiorcy w wyniku zastosowania nakładki krawędziowej.
    Article presents model investigations of sound barrier in non-echo chamber in 1:1 scale together with some shape edge cover. Achieved results are a base to qualitatively and quantitatively evaluation of used edge cover design account distribution of sound field behind sound barrier on the receiver side as a results of used edge cover.
    Źródło:
    Fizyka Budowli w Teorii i Praktyce; 2011, T. 6, nr 4, 4; 15-20
    1734-4891
    Pojawia się w:
    Fizyka Budowli w Teorii i Praktyce
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Estimation of Acoustic Impedance for Surfaces Delimiting the Volume of an Enclosed Space
    Autorzy:
    Piechowicz, J.
    Czajka, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/177215.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic impedance
    acoustic measurements
    numerical methods
    sound field
    Opis:
    Several methods can be applied for analyses of the acoustic field in enclosed rooms namely: wave propagation, geometrical or statistical analysis. The paper presents problems related to application of the boundary elements method to modelling of acoustic field parameters. Experimental and numerical studies have been combined for evaluation of acoustic impedance of the material used for the walls of a model room. The experimental studies have been carried out by implementing a multichannel measuring system inside the constructed model of an industrial room. The measuring system allowed simultaneous measurements of the source parameters – the loudspeaker membrane vibration speed, the acoustic pressure values in reception points located inside the model space as well as phase shifts between signals registered in various reception points. The numerical modelling making use of the acoustic pressure values measured inside the analyzed space allowed determination of requested parameters of the surface at the space boundary.
    Źródło:
    Archives of Acoustics; 2012, 37, 1; 97-102
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Design of Acoustic Tubes Array and Application to Measuring Acoustic Loads in Supersonic Airflow
    Autorzy:
    Wei, L.
    Li, M.
    Fu, Q.
    Fan, Y.
    Yang, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/176750.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic load
    acoustic tubes array
    near field measurement
    supersonic airflow
    Opis:
    In the acoustic fatigue experiment for hypersonic vehicle in simulated harsh service environment on ground, acoustic loads on the surface of test pieces of the vehicle need to be measured. However, for the normal microphones without high temperature resistance ability, the near field sound measurement cannot be achieved. In this work, on the basis of previous researches, an acoustic tubes array is designed to achieve the near field measurement of acoustic loads on the surface of the test piece in the supersonic airflow with high temperature achieved by coherent jet oxygen lance. Firstly, the process of designing this acoustic tubes array is introduced. Secondly, the equality of phase differences at the front and at the end of the tubes is stated and proved using a phase differences test with an acoustic tubes array whose design is presented in this text; therefore, the phase differences of signals acquired by microphones can be directly applied to beamforming algorithm to determine the acoustic load source. Finally, using above mentioned acoustic tubes array, measurement of acoustic load, with and without a test piece in the supersonic airflow made by the coherent jet oxygen lance, is conducted respectively, and the measurements results are analyzed.
    Źródło:
    Archives of Acoustics; 2014, 39, 3; 395-402
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Systematic error of acoustic particle image velocimetry and its correction
    Autorzy:
    Mickiewicz, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/221013.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    particle image velocimetry
    acoustic measurement
    acoustic particle velocity
    sound field analysis
    Opis:
    Particle Image Velocimetry is getting more and more often the method of choice not only for visualization of turbulent mass flows in fluid mechanics, but also in linear and non-linear acoustics for non-intrusive visualization of acoustic particle velocity. Particle Image Velocimetry with low sampling rate (about 15Hz) can be applied to visualize the acoustic field using the acquisition synchronized to the excitation signal. Such phase-locked PIV technique is described and used in experiments presented in the paper. The main goal of research was to propose a model of PIV systematic error due to non-zero time interval between acquisitions of two images of the examined sound field seeded with tracer particles, what affects the measurement of complex acoustic signals. Usefulness of the presented model is confirmed experimentally. The correction procedure, based on the proposed model, applied to measurement data increases the accuracy of acoustic particle velocity field visualization and creates new possibilities in observation of sound fields excited with multi-tonal or band-limited noise signals.
    Źródło:
    Metrology and Measurement Systems; 2014, 21, 3; 447-460
    0860-8229
    Pojawia się w:
    Metrology and Measurement Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Velocity Field Characteristics at the Inlet to a Pipe Culvert
    Autorzy:
    Kolerski, T.
    Wielgat, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/241162.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
    Tematy:
    Culvert
    Acoustic Doppler Velocitymeter
    velocity field
    turbulence
    Opis:
    A poorly designed culvert inlet structure causes scouring, which can lead to the collapse of the culvert and significant damage to the neighboring land. A set of laboratory tests was evaluated to examine velocity distribution at the culvert inlet. A three-dimensional acoustic Doppler velocimeter was used to measure instantaneous flow velocity upstream of the culvert. The analysis of mean velocities, turbulence strength, and Reynolds stresses was performed to understand the flow structure near the culvert entrance.
    Źródło:
    Archives of Hydro-Engineering and Environmental Mechanics; 2014, 61, 3-4; 127--140
    1231-3726
    Pojawia się w:
    Archives of Hydro-Engineering and Environmental Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sound Radiation of a Pulsating Sphere in the Outlet of a Hard/Soft Semi-Spherical Cavity in a Flat Screen
    Autorzy:
    Rdzanek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/950213.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Neumann/Dirichlet problem
    sound field
    acoustic impedance
    continuity
    Opis:
    A rigorous analysis of sound radiation by a pulsating sphere forming a resonator together with a semispherical cavity is presented. Both hard and soft boundaries are considered, as well as mixed. The problem is solved by dividing the entire region into two subregions, one surrounding the sphere and containing the cavity and the other for the remaining half-space. The continuity conditions are applied to obtain the acoustic pressure. Then the acoustic radiation resistance is calculated both in the near- and far-field. The acoustic radiation reactance is calculated in the impedance approach. The resonance frequencies are determined, for which a significant growth of the sound pressure level is observed as well as the sound field directivity. The accuracy and convergence of these rigorous results has been examined empirically.
    Źródło:
    Archives of Acoustics; 2016, 41, 1; 75-86
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active Transient Sound Radiation Control from a Smart Piezocomposite Hollow Cylinder
    Autorzy:
    Hasheminejad, S. M.
    Rabbani, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/177572.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active structural acoustic control (ASAC) thick cylindrical shells
    exact elasto-acoustic analysis
    time-domain solution
    intelligent system
    sound field attenuation
    Opis:
    The linear 3D piezoelasticity theory along with active damping control (ADC) strategy are applied for non-stationary vibroacoustic response suppression of a doubly fluid-loaded functionally graded piezolaminated (FGPM) composite hollow cylinder of infinite length under general time-varying excitations. The control gain parameters are identified and tuned using Genetic Algorithm (GA) with a multi-objective performance index that constrains the key elasto-acoustic system parameters and control voltage. The uncontrolled and controlled time response histories due to a pair of equal and opposite impulsive external point loads are calculated by means of Durbin’s numerical inverse Laplace transform algorithm. Numerical simulations demonstrate the superior (good) performance of the GA-optimized distributed active damping control system in effective attenuation of sound pressure transients radiated into the internal (external) acoustic space for two basic control configurations. Also, some interesting features of the transient fluid-structure interaction control problem are illustrated via proper 2D time domain images and animations of the 3D sound field. Limiting cases are considered and accuracy of the formulation is established with the aid of a commercial finite element package as well as comparisons with the current literature.
    Źródło:
    Archives of Acoustics; 2015, 40, 3; 359-381
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Calculation for Acoustic Radiation Force from Rectangular Weakly Focusing Transducer Using the Ray Acoustic Model
    Autorzy:
    Yu, Lili
    Qiao, Shuchang
    Shou, Wende
    Li, Junhua
    Powiązania:
    https://bibliotekanauki.pl/articles/2141691.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    radiation force calculation
    ray acoustic model
    rectangular weakly focusing transducer
    far-field integration
    Opis:
    Based on the ray acoustic model, a new relationship between the radiation force and the acoustic power is studied for a rectangular weakly focusing transducer. The effect of pressure reflection coefficient on this model is discussed. For a totally absorbing target, an approximate closed-form expression is also derived and the performance of this model is compared with that of the far-field integration model. The numerical results show that the agreement is excellent with these two models, which can be both used for correction of measured results, but the formula based on the ray acoustic model can be applied more widely in practice because of its simpler expression. The experimental results show further the effectiveness of the relationship between radiation force and acoustic power for rectangular weakly focusing transducer based on the ray acoustic model. The results presented in this paper are important for application of ultrasound transducers in therapy.
    Źródło:
    Archives of Acoustics; 2022, 47, 1; 81-88
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sound Field Modelling and Noise Reduction for a Forklift Power Compartment Based on Perfectly Matched Layer and Acoustic Packaging Design
    Autorzy:
    Zhang, Enlai
    Liu, Zhiqi
    Zhang, Jingjing
    Lin, Jiahe
    Powiązania:
    https://bibliotekanauki.pl/articles/1945640.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    forklift power compartment
    sound field modelling
    perfectly matched layer
    acoustic packaging design
    noise reduction
    Opis:
    The core goal of this paper is to put forward a feasible scheme of noise reduction for a target forklift on the basis of solving the problem of vibration and acoustic radiation from complex structures in infinite domain. Based on the previous report and vibration acceleration tests, the acoustic virtual wind tunnel model of forklift power compartment was established using finite element method and boundary element method, in which the perfectly matched layer was first applied to simulate the attenuation propagation of sound waves in air. In addition, according to the distribution characteristics of sound pressure field with different frequencies, the acoustic energy mainly radiated through the bottom and right side, and concentrated in the low frequency. Consequently, the acoustic packaging design for the whole forklift power compartment was presented, and a satisfying noise reduction effect was achieved.
    Źródło:
    Archives of Acoustics; 2021, 46, 3; 491-498
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ocena efektywności sposobów zwiększania rozdzielczości danych sejsmicznych w poszukiwaniach węglowodorów w świetle zastosowanej metodyki akwizycji i procedur modyfikacji spektralnej
    Evaluation of the efficiency of the methods of increasing seismic data resolution in exploration of hydrocarbons in light of the applied acquisition methodology and procedures of spectral modification – real case study
    Autorzy:
    Jędrzejowska-Tyczkowska, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1835107.pdf
    Data publikacji:
    2018
    Wydawca:
    Instytut Nafty i Gazu - Państwowy Instytut Badawczy
    Tematy:
    rozdzielczość danych sejsmicznych
    zakres częstotliwości w sejsmicznym obrazie falowym
    modyfikacja spektralna obrazu falowego
    projektowanie schematu akwizycji
    krotność sumowania
    inwersja sejsmiczna
    profilowanie akustyczne
    resolution of seismic data
    frequency range of seismic wavefield image
    wavefield image spectral modification
    seismic survey acquisition design
    field-coverage stacking
    seismic inversion
    acoustic profiling
    Opis:
    Porównano efektywność sposobów zwiększania rozdzielczości danych sejsmicznych realizowanych na dwóch różnych etapach projektów sejsmicznych 3D, a to w drodze projektowania zaawansowanych schematów akwizycji, umożliwiających uzyskiwanie obrazu falowego o bardzo wysokiej krotności sumowania (rzędu 2260), jak też w drodze stosowania procedur przetwarzania w domenie spektralnej o (autorskiej) nazwie „modyfikacja spektralna”. Artykuł jest czwartą publikacją omawiającą powyższe zagadnienie w optyce innowacyjnej opracowanej przez autorkę w ramach realizacji jednego z zadań programu Blue Gas – Polski Gaz Łupkowy. Przedstawione w artykule porównania wskazują, że zastosowanie określonej metodyki istotnie zależy od jakości materiału sejsmicznego. W niniejszej pracy wykorzystano obraz falowy uzyskany od zleceniodawcy (migracja czasowa na sumie – migration AFTER STACK). Na podstawie wykonanych porównań należy sądzić, że decyzja o wyborze sposobu zwiększania rozdzielczości powinna brać pod uwagę aspekt ekonomiczny końcowej realizacji.
    Comparison of the efficiency of the methods for increasing the resolution of seismic data was performed at two different stages of 3D seismic survey design, by creating advanced acquisition schemes to obtain a very high fold-coverage stacking (with the range of 2260), as well as using processing procedures in the spectral domain – “spectral modification”. This article is the fourth publication discussing the issue above, developed by the author within one of the tasks of the Blue Gas – Polski Gaz Łupkowy program. The comparison presented in this paper indicates, that the application of a particular methodology, depends on the quality of the seismic data. In this study a wavefield image obtained from the client (After Stack time migration) was used based on the comparisons made, it should be assumed that the decision on choosing the method of increasing the resolution should take into account the economic aspect of the final implementation.
    Źródło:
    Nafta-Gaz; 2018, 74, 1; 3-21
    0867-8871
    Pojawia się w:
    Nafta-Gaz
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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