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    Wyświetlanie 1-19 z 19
    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:
    Total Acoustic Power of Two Concentric Clamped Circular Plates Vibrating in a Fluid
    Autorzy:
    Rdzanek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402179.pdf
    Data publikacji:
    2015-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Bi
    43.20.El
    43.20.Fn
    43.20.Rz
    Opis:
    This study focuses on the problem of sound radiation by two concentric clamped flat plates, circular and annular, into the half-space. The system of three coupled differential equations comprising two equations of motions of plates and the wave equation, is solved exactly. Vibrations of plates are axisymmetric and time-harmonic with a single excitation frequency. The initial phase difference of excitations can be nonzero. Attenuation due to fluid loading and material damping is included. Kirchoff-Love and Kelvin-Voigt theories are applied. The effect of initial phase difference of excitations on the acoustic power radiated is examined as well as errors resulting from neglecting the fluid loading.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 1A; A-41-A-45
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Asymptotic formulae for the acoustic self-impedance of simply-supported and simply supported-clamped annular plates
    Wyznaczanie akustycznej impedancji własnej płaskich płyt pierścieniowych o różnych konfiguracjach brzegowych z zastosowaniem równań asymptotycznych
    Autorzy:
    Rdzanek, W. P.
    Rdzanek, W. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/973169.pdf
    Data publikacji:
    2014
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    active and reactive self-impedance
    sound radiation for the high frequencies
    annular flat plate in a rigid baffle
    promieniowanie dźwięku dla wysokich częstości
    czynna i bierna impedancja własna
    łaskie płyty pierścieniowe w sztywnej odgrodzie
    Opis:
    This study focuses on the sound radiation of a vibrating flat annular plate. The rigorous theoretical considerations deal with some time-harmonic and axisymmetric vibrations. Three different boundary configurations are considered, i.e. one of the plate's edges is simply supported and the other one is clamped or also is simply supported. The active and reactive self-impedance of the system are presented in their Hankel's representations, valid within the whole frequency spectrum. The expressions obtained are transformed to their elementary forms, valid for the high frequencies. Low fluid loading and low internal friction of the plate are assumed. The obtained results are illustrated with sample plots in the domain of acoustic wave number. Elementary formulae presented can be useful for further theoretical analysis of the total sound power radiated by an excited flat plate in an acoustic fluid as well as for efficient engineering computations.
    W pracy podjęto zagadnienie promieniowania dźwięku przez drgającą płaską płytę pierścieniową. Ścisłe rozważania teoretyczne dotyczą osiowosymetrycznych drgań harmonicznych. Rozpatrzono trzy różne konfiguracje brzegowe, tj. dla jednej krawędzi płyty swobodnie podpartej, a drugiej utwierdzonej łub swobodnie podpartej. Czynną i bierną impedancję własną układu drgającego przedstawiono w reprezentacji Hankela, słusznej w całym spektrum częstości. Wyrażenia te zostały przekształcone do ich elementarnych postaci, słusznych dla wysokich częstości. Założono, że wpływ powietrza na drgania płyty oraz tłumienie wewnętrzne są znikome. Otrzymane wyniki zilustrowano wybranymi wykresami w funkcji liczby falowej. Przedstawione wzory elementarne mogą być przydatne do dalszej analizy teoretycznej całkowitej mocy promieniowania dźwięku przez płaską płytę pobudzoną do drgań z uwzględnieniem wpływu ośrodka, jak również do szybkich obliczeń inżynierskich.
    Źródło:
    Mechanics and Control; 2014, 33, 1; 17-25
    2083-6759
    2300-7079
    Pojawia się w:
    Mechanics and Control
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The acoustic power radiated by a circular membrane excited for vibration both by means of the edge and by external surface load
    Autorzy:
    Szemela, K.
    Rdzanek, W. P.
    Rdzanek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/176879.pdf
    Data publikacji:
    2005
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic radiation power
    vibrations of a spherical membrane
    excitation produced by edge and surface loads
    amplitude-phase effects
    Opis:
    In this paper the acoustic power of the circular membrane, excited both by the edge and external exciting forces uniformly distributed over the whole surface, is examined. Some different amplitudes of exciting factors and some differences between the phases of excitations were considered. It has been assumed that the source of a sound is located in a flat, rigid and infinite baffle and is sourrounded by a lossless and homogeneous fluid medium. The vibrations are axisymmetric and time-harmonic. Employing the Cauchy's theorem of residues and asymptotic formulae for the Bessel functions, the asymptotes for active and reactive power consisting of elementary functions are obtained. The acoustic power radiated by the membrane was shown graphically in terms of the parameters describing both kinds of excitations.
    Źródło:
    Archives of Acoustics; 2005, 30, 1; 109-119
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The reactive sound power of a circular plate within the low frequencies
    Moc bierna dźwięku płyty kołowej w zakresie niskich częstości
    Autorzy:
    Rdzanek, W. P.
    Rdzanek, W.
    Zawieska, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/328105.pdf
    Data publikacji:
    2005
    Wydawca:
    Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
    Tematy:
    bierna moc dźwięku
    numer modu
    promieniowanie dźwięku
    reactive sound-power
    mode number
    sound radiation
    Opis:
    An efficient low frequency approximation for the reactive sound power of an elastically supported circular plate has been directly derived from the corresponding high frequency expressions presented earlier. The analysis of the approximation error has shown that the low frequency formulation can be applied if the error of 10% can be accepted. The result is valid for any axisymmetric boundary configuration of the plate. The influence of the boundary configuration on the reactive sound power has been examined.
    Efektywną aproksymację niskoczęstościową biernej mocy dźwięku płyty kołowej zamocowanej sprężyście wyprowadzono bezpośrednio z odpowiednich wyrażeń wysokoczęstościowych przedstawionych wcześniej. Analiza błędów aproksymacji pokazała, że wzór niskoczęstościowy może być stosowany, jeśli dopuszczalny błąd względny może wynosić do 10%. Otrzymany wynik jest słuszny dla dowolnej osiowosymetrycznej konfiguracji brzegowej płyty. Zbadano wpływ konfiguracji brzegowej na moc bierną.
    Źródło:
    Diagnostyka; 2005, 34; 59-62
    1641-6414
    2449-5220
    Pojawia się w:
    Diagnostyka
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Acoustic Impedance of a Vibrating Annular Piston Located on a Flat Rigid Baffle Around a Semi-Infinite Circular Rigid Cylinder
    Autorzy:
    Rdzanek, W. P.
    Rdzanek, W. J.
    Pieczonka, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/176618.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Neumann boundary value problem
    annular piston
    acoustic impedance
    semi-infinite cylindrical circular rigid baffle
    Opis:
    The axisymmetric problem of acoustic impedance of a vibrating annular piston embedded into a flat rigid baffle concentrically around a semi-infinite rigid cylindrical circular baffle has been undertaken in this study. The Helmholtz equation has been solved. The Green’s function valid for the zone considered has been used for this purpose. The influence of the semi-infinite cylindrical baffle on the piston’s acoustic impedance has been investigated. The acoustic impedance has been presented in both forms: integral and asymptotic, both valid for the steady harmonic vibrations. Additionally, the acoustic impedances of the piston with and without the cylindrical baffle have been compared to one another. In the case without the cylindrical baffle some earlier results have been used.
    Źródło:
    Archives of Acoustics; 2012, 37, 4; 411-422
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Moc promieniowania dźwięku przez płytę kołową zamocowaną przegubowo w zakresie niskich częstotliwości
    The sound power of a simple-supported circular plate for low frequencies
    Autorzy:
    Rdzanek, W. J.
    Engel, Z.
    Rdzanek, W. P.
    Powiązania:
    https://bibliotekanauki.pl/articles/332047.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Opis:
    A computation method and the resultant formulas for the active sound power of axisymmetric free vibrations of a circular plate simply supported by a planar rigid baffle have been presented in the paper. Processes sinusoidally varying in time have been considered. It has been assumed that there are no reflexive influences of the air column over the plate and the baffle on the plate's vibrations. The integral formula for the active sound radiation in the Hankel's representation of null order has been transformed to a formula in an elementary form. This elementary formula contains the Bessel's and the Struve's functions of null and first orders and is valid for a relatively wide range of low frequencies.
    Źródło:
    Hydroacoustics; 2000, 3; 225-230
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The acoustic radiation impedance of a circular membrane vibrating near the three-wall corner
    Autorzy:
    Rdzanek, W. P.
    Rdzanek, W. J.
    Szemela, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/331634.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    sound radiation
    acoustic radiation impedance
    circular membrane
    Opis:
    A flat circular membrane is located near the three- wall corner, limited by the three rigid baffles arranged perpendicularly to each other. The problem of sound radiation has been solved using the spectral form of the Green function for this Neumann boundary value problem together with the complete eigenfunction system of the axisymmetric and asymmetric modes of the membrane is excited by a surface vibrating harmonically with respect to time within the vacuum. The membrane is excited by a surface force. The acoustic attenuation 3399effect has been taken into account as well as the influence of the corner baffles. The resultant sound pressure and the resultant acoustic impedance have been presented as their eigenfunction series. The modal, self and mutual, radiation resistance has been presented in the form of the approximation valid within the low frequency vibration range. The low frequency approximation for the modal radiation reactance has been obtained on the basis of the radiation resistance using the Hilbert transform.
    Źródło:
    Hydroacoustics; 2008, 11; 339-352
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustic Power Radiated by a System of Two Vibrating Circular Membranes Located at the Boundary of Three-Wall Corner Spatial Region
    Autorzy:
    Szemela, K.
    Rdzanek, W. P.
    Rdzanek, W. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176658.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    three-wall corner region
    Green function
    Neumann boundary value problem
    modal analysis
    asymmetric vibrations
    vibration of an excited circular membrane
    acoustic power
    mutual interaction of sound sources
    Opis:
    Two vibrating circular membranes radiate acoustic waves into the region bounded by three infinite baffles arranged perpendicularly to one another. The Neumann boundary value problem has been inves- tigated in the case when both sources are embedded in the same baffle. The analyzed processes are time harmonic. The membranes vibrate asymmetrically. External excitations of different surface distributions and different phases have been applied to the sound sources’ surfaces. The influence of the radiated acoustic waves on the membranes’ vibrations has been included. The acoustic power of the sound sources system has been calculated by using a complete eigenfunctions system.
    Źródło:
    Archives of Acoustics; 2012, 37, 4; 463-473
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Acoustic Pressure Radiated by a Vibrating Circular Plate within the Fraunhofer Zone of the Three-Wall Corner Region
    Autorzy:
    Szemela, K.
    Rdzanek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1490263.pdf
    Data publikacji:
    2012-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Ks
    43.20.Rz
    43.40.+s
    43.20.-f
    43.20.+g
    Opis:
    The Neumann boundary value problem has been solved for the region bounded by the three perfect rigid infinite baffles arranged perpendicularly to one another. The harmonically vibrating clamped circular plate embedded in one of the baffles is the sound source. It has been assumed that the amplitude of the plate's transverse vibrations is small to use the linear Kelvin-Voigt theory. The Green function has been applied to obtain the asymptotic formulae describing the distribution of the acoustic pressure within the Fraunhofer zone. The analysis of sound radiation has been performed for some selected surface excitations and for some different plate's locations. The acoustic pressure distribution has been examined including the acoustic attenuation and the internal attenuation of the plate's material.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 1A; A-100-A-109
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Low Frequency Approximation of the Sound Radiation Power of Two Vibrating Circular Pistons Embedded in Two Different Rigid Planes of a Three-wall Corner
    Autorzy:
    Rdzanek, W.
    Szemela, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1196854.pdf
    Data publikacji:
    2014-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Bi
    43.20.El
    43.20.Fn
    43.20.Rz
    Opis:
    The problem of sound radiation by a system consisting of two vibrating circular pistons embedded in two of three different planes perpendicular to one another forming a three-wall corner is considered. The earlier published results dealing with the sound radiation by sources vibrating in a three-wall corner are the basis of analysis. According to the earlier studies, the exact formulae for acoustic power of radiation of two circular pistons are used. The formulae are expressed as double Fourier integrals. The active and reactive, self and mutual, components are separated from them as well as the corresponding expressions of the acoustic power of mirror images of the piston sources. The acoustic power of the two sources are expressed in the form of the Rayleigh formulae whereas, in the case of the mirror images, it is expressed in the form of the single series expansion containing spherical Bessel and Neumann functions. In the case of the mutual acoustic power of the sources, approximate formulae are presented for low frequencies. On the basis of the results obtained, the corresponding formulae valid for a two-wall corner are presented as the limiting transitions. All the results presented can be useful, e.g. in designing the room acoustics and outdoor system everywhere the free field conditions are disturbed by the acoustic waves reflected at rigid vertical walls for the wavelengths being considerably shorter than the geometric sizes of the walls.
    Źródło:
    Acta Physica Polonica A; 2014, 125, 4A; A-135-A-143
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Asymptotic Formulae of the Modal Acoustic Impedance for the Asymmetric Vibrations of a Clamped Circular Plate
    Autorzy:
    Rdzanek, W.
    Szemela, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1537549.pdf
    Data publikacji:
    2010-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Ks
    43.20.Rz
    43.40.+s
    Opis:
    The asymptotic and approximate formulae for the asymmetric modal acoustic self- and mutual-impedance have been presented for a clamped circular plate embedded into a flat rigid baffle. The formulae have been obtained for the wide frequency band covering the low frequencies, the high frequencies and the middle frequencies. The high frequency asymptotics have been achieved using the method of contour integral and the method of stationary phase. The products of the Bessel and Neumann functions have been expressed as the asymptotic expansions. Further, the approximate formulae valid within the low and middle frequencies have been obtained from the high frequency asymptotics using some mathematical manipulations. The formulae presented are valid for both the axisymmetric vibrations and the asymmetric vibrations.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 1; 141-154
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustic Impedance of an Annular Piston Wobbling in a Flat Screen Around a Semi-infinite Circular Cylinder
    Autorzy:
    Pieczonka, D.
    Rdzanek, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1400095.pdf
    Data publikacji:
    2013-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Bi
    43.20.El
    43.20.Fn
    43.20.Rz
    Opis:
    A rigorous solution is presented for the problem of sound radiation by an oscillating and wobbling annular piston embedded concentrically in a perpendicular flat screen surrounding a semi-infinite circular cylindrical baffle. Two forms of the Green's function of the considered region are used. The acoustic impedance is presented in its integral form useful for numerical calculations which enable studying the effect of the acoustic waves scattering on the cylindrical baffle and the asymmetry of vibration velocity on the piston on the resultant acoustic impedance of the wobbling piston. It is shown that in the case of the vibrating piston under consideration, the reciprocity of acoustic impedance related to two modes of rigid body motion, oscillating and wobbling, does not occur.
    Źródło:
    Acta Physica Polonica A; 2013, 123, 6; 1078-1084
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Modal Low Frequency Noise of an Elastically Supported Circular Plate
    Autorzy:
    Rdzanek, W. P.
    Rdzanek, W. J.
    Engel, Z.
    Szemela, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/89877.pdf
    Data publikacji:
    2007
    Wydawca:
    Centralny Instytut Ochrony Pracy
    Tematy:
    low frequency noise
    radiation efficiency
    circular plate
    hatchway
    Opis:
    The modal low frequency noise generated by a vibrating elastically supported circular plate embedded into a flat infinite baffle has been examined. The main aim of this study is the analysis of the radiation efficiency. Low frequency approximated formulas have been presented. They are valid for all the limiting boundary conditions of the plate with its edge clamped, guided, simply supported or free as well as for all the intermediate axisymmetric boundary configurations. The formulas are expressed in the elementary form, useful for numerical computations. They are a generalization of some earlier published results. First, they are valid for axisymmetric and asymmetric modes since both kinds of modes play an important role in the low frequency range. Second, a single formula for the radiation efficiency, valid for all the axisymmetric boundary configurations, has been proposed. A numerical example for the sound power radiation has been given for some hatchway covers mounted on a ship deck.
    Źródło:
    International Journal of Occupational Safety and Ergonomics; 2007, 13, 2; 147-157
    1080-3548
    Pojawia się w:
    International Journal of Occupational Safety and Ergonomics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Total Acoustic Power of a Clamped Circular Plate Located at the Boundary of Three-Wall Corner Region
    Autorzy:
    Szemela, K.
    Rdzanek, W.
    Pieczonka, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/1504426.pdf
    Data publikacji:
    2011-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    43.20.Ks
    43.20.Rz
    43.40.+s
    43.20.-f
    43.20.+g
    Opis:
    The energetic aspect of the sound radiation has been analyzed in the case of the three-wall corner region. This region is the part of space bounded by three baffles arranged perpendicularly to one another. The Neumann boundary value problem has been solved assuming that the sound source is the vibrating circular plate embedded in one of the baffles of the three-wall corner region. The Kelvin-Voigt theory of a visco-elastic plate has been used which allows to include internal attenuation existing in the plate material. It has been assumed that the sound source is excited to vibrations by the external pressure asymmetrically distributed on the plate surface. The modal coefficients of the acoustic impedance have been obtained in the form of the expressions containing single integrals only. The formula describing the acoustic power of the analyzed sound source has been presented as a fourfold infinite series containing the modal coefficients of the acoustic impedance. The influence of some asymmetric excitations on the acoustic power has been analyzed. The possibilities of the modelling some uniform excitations located on the plate fragment of the small area by the point force excitation has been examined. The influence of the transverse baffles on the acoustic power has also been investigated. It has been determined for which frequency the baffles influence on the acoustic power is the greatest.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 6A; 1050-1060
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acoustic Pressure Radiated by a Circular Membrane Into the Quarter-Space
    Autorzy:
    Rdzanek, W. P.
    Szemela, K.
    Pieczonka, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/177368.pdf
    Data publikacji:
    2011
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic pressure
    Fraunhoffer's zone
    Green function
    circular membrane
    Opis:
    The Neumann boundary value problem for the Helmholtz equation within the quarter-space has been considered in this paper. The Green function has been used to find the acoustic pressure amplitude as the approximation valid within the Fraunhoffer’s zone for some time-harmonic steady state processes. The low fluid loading has been assumed and the acoustic attenuation has been neglected. It has also been assumed that the vibration velocity of the acoustic particles is small as compared with the sound velocity in the gaseous medium.
    Źródło:
    Archives of Acoustics; 2011, 36, 1; 121-139
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Radiation Efficiency Measurements of Real System of a Thin Circular Plate Embedded Into a Thick Square Baffle
    Autorzy:
    Szemela, K.
    Rdzanek, W. P.
    Żyłka, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/176336.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    radiation efficiency
    measurements
    Hashimoto’s method
    coupled plates
    Opis:
    Most of sound sources are complex vibroacoustic objects consist of numerous elements. Some coupled vibrating plates of different shapes and sizes can be easily found in urban environments. The main aim of this study is to determine the sound radiation of coupled plates system of practical importance. The investigated vibroacoustic system consist of a thin circular plate coupled with a thick flat baffle with a circular hole. The circular plate has been mounted to the baffle’s hole using screws and two steel rings. The measurement setup was located inside a semi-anechoic chamber to assure the free field conditions. It was necessary to take into account the whole system surface to obtain the radiation efficiency based on the Hashimoto’s method. Such an approach can be troublesome and time-consuming. Therefore, the criterion has been proposed which allows the vibration velocity measurements and calculations to be performer only for the thin plate’s area. An alternative approach has been proposed based on the classical Rayleigh integral formula. Its advantage is a simpler implementation in a computer code. The obtained results have been compared with the theoretical results obtained for the elastically supported circular plate. A good agreement has been obtained at low frequencies.
    Źródło:
    Archives of Acoustics; 2018, 43, 3; 413-423
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Perwaporacyjne zatężanie układu butanol-etanol-aceton-woda na membranach komercyjnych
    The butanol-ethanol-acetone-water recovery by pervaporation using commercial membranes
    Autorzy:
    Rdzanek, P.
    Marszałek, J.
    Kamiński, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/126098.pdf
    Data publikacji:
    2015
    Wydawca:
    Towarzystwo Chemii i Inżynierii Ekologicznej
    Tematy:
    perwaporacja
    membrana
    biobutanol
    pervaporation
    membrane
    Opis:
    Perwaporacja (PV) jest procesem membranowym, w którym rozdział składników następuje na selektywnej warstwie membrany, która może być polimerowa, ceramiczna bądź kompozytowa. Zastosowanie perwaporacji, w miejsce konwencjonalnych metod odwadniania rozpuszczalników tworzących z wodą mieszaniny azeotropowe, przynosi, oprócz niewymiernych korzyści w ochronie środowiska, także konkretne korzyści ekonomiczne. Badania przeprowadzone w pracy skupiają się na separacji butanolu z wodnego roztworu ABE (aceton-butanol-etanol). Dotychczas jako dodatek do paliw stosowano etanol, obecnie w badaniach więcej uwagi poświęca się n-butanolowi ze względu na jego właściwości zbliżone do benzyny. W pracy przetestowano różne typy komercyjnych membran perwaporacyjnych (o różnym składzie warstwy aktywnej). Badania prowadzono na membranie PERVAP 4060 oraz na membranach firmy PERVATECH. Proces perwaporacji wykonano na laboratoryjnej aparaturze o powierzchni membrany 50,24 cm2. Proces prowadzony był przy natężeniu przepływu nadawy 40 dm3/h, dla temperatury roztworu zasilającego 29, 37 i 50°C i ciśnieniu po stronie permeatu 10 mbar. Stężenia butanolu w nadawie wynosiły 1,5, 3 i 5% wag. Przeanalizowano wpływ rodzaju warstwy aktywnej membrany na zmianę strumienia butanolu oraz współczynnika wzbogacenia składnika w permeacie. Skład permeatu i retentatu analizowany był za pomocą chromatografii gazowej.
    Pervaporation (PV) is a membrane-based process employing dense polymer, ceramic or innovate components materials as active separation layer. The use of pervaporation compared to the conventional methods for dehydration solvents forming an azeotrope with water brings, besides unquantifiable benefits in environmental also economic benefits. In this paper PV process is used to separate and concentrate biobutanol from the ABE (acetone-butanol-ethanol) water solution. So far as an additive for fuel ethanol was used, currently in research more attention is given to n-butanol, because of its properties closed to gasoline Different types of commercial membranes are tested in pervaporation experimental setup. Research was carried out on the PERVAP 4060 and PERVATECH membranes. The research was conducted on a laboratory apparatus, where the membrane diameter was 50.24 cm2. The pervaporation was carried out with the feed flow rate 40 dm3/h, the permeate side pressure 10 mbar and the feed temperature 29, 37 and 50°C. The concentrations of butanol in feed was 1.5, 3 and 5 wt.%. The influence of the active layer composition on the butanol flux and the enrichment coefficient was analyzed. The composition of permeate and retentate was analyzed by gas chromatography.
    Źródło:
    Proceedings of ECOpole; 2015, 9, 2; 693-698
    1898-617X
    2084-4557
    Pojawia się w:
    Proceedings of ECOpole
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The influence of hydrodynamic conditions on the recovery of acetone, butanol and ethanol in pervaporation membrane modules
    Autorzy:
    Marszałek, J.
    Tylman, M.
    Rdzanek, P.
    Kamiński, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/185317.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    pervaporation
    membrane module
    flow modeling
    biobutanol
    perwaporacja
    moduł membranowy
    modelowanie przepływu
    Opis:
    In order to assess the influence of hydrodynamic effects on the recovery of n-butanol by means of pervaporation, a commercial PERVAP 4060 membrane was investigated. Laboratory pervaporation experiments were carried out providing a comparison of the permeation fluxes and enrichment factors. While the enrichment factors achieved in both modules under the same process conditions were comparable, the permeation fluxes differed from each other. In order to explain the observed differences, hydrodynamic conditions in the membrane module were examined by means of CFD simulation performed with ANSYS Fluent 14.5 software. Two different modules having membrane diameters of 80 mm and 150 mm were analyzed. As a result, different velocity profiles were obtained, which served to estimate the mass transfer coefficients of butanol, ethanol and acetone.
    Źródło:
    Chemical and Process Engineering; 2018, 39, 2; 155--163
    0208-6425
    2300-1925
    Pojawia się w:
    Chemical and Process Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-19 z 19

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