Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "bubbles" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-3 z 3
    Tytuł:
    The acoustic excitation of newly-formed bubbles
    Autorzy:
    Deane, G.
    Czerski, H.
    Stokes, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/331506.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    gas bubbles
    hydroacoustics
    natural frequency
    Opis:
    Gas bubbles in water act as oscillators with a natural frequency inversely proportional to their radius and a quality factor determined by thermal, radiation, and viscous losses. Newly-formed gas bubbles are excited into breathing mode oscillations immediately after creation, causing them to radiate a pulse of sound. Although the linear dynamics of spherical gas bubbles are well-understood, the mechanism driving the sound production has not been unambiguously identified. Using bubbles released from a nozzle as a model system, it can be shown that sound production is consistant with the rapid change in volume associated with the collapse of an air neck formed immediately after bubble pinch-off. The model is able to adequately describe the production of sound by bubbles released from a nozzle, and can also explain some of the acoustic properties of bubbles fragmenting in fluid turbulence. Laboratory experiments and model calculations of the mechanism are presented. [Work supported by ONR and NSF].
    Źródło:
    Hydroacoustics; 2008, 11; 71-78
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Towards field measurement of populations of methane gas bubbles in marine sediment: an inversion method required for interpreting two-frequency insonification data from sediment containing gas bubbles
    Autorzy:
    Leighton, T.
    Mantouka, A.
    White, P.
    Klusek, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/331678.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    methane
    marine sediment
    gas bubbles
    Opis:
    This paper describes a key stage in the process for developing a new device for the measurement of gas bubbles in sediment. The device is designed to measure gas bubble populations within the top 2 m of marine sediments, and has been deployed at inter-tidal sites along the South coast of England. Acoustic techniques are particularly attractive for such purposes because they can be minimally invasive. However they suffer from the limitation that their results can be ambiguous. Therefore it is good practice to deploy more than one acoustic technique at time. The new device does just this, but it is designed with the practical economy that the task is accomplished with the minimum number of transducers. One of the measurement techniques relies on insonifying the sediment with two frequencies. This paper outlines how the bubble size distribution is inferred through inversion of the signals detected when two frequencies are projected into the sediment. The high attenuation of the sediment makes this interpretation far more difficult that it would be in water. This paper outlines these difficulties and describes how they can be overcome.
    Źródło:
    Hydroacoustics; 2008, 11; 203-224
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Impact of salinity on the underwater noise generated by small scale air entrainment events
    Autorzy:
    Szuszkiewicz, J.
    Klusek, Z.
    Gorska, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/332616.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Akustyczne
    Tematy:
    underwater noise
    air entrainment
    bubbles
    bubble clusters
    Opis:
    Some part of the energy released in the wave breaking process is transformed into the energy of the noise. This sound depends on the water properties, however, there is a lack of reliable data concerning the underwater noise generated by less energetic events. The aim of this study was to understand the impact of salinity on the underwater noise produced during small scale air entrainment events, typical for low wind speed conditions. The tipping trough experiment was performed in a small tank to generate the small scale air injections. Four, linearly placed hydrophones HTI-96-MIN were used to record the acoustic noise accompanying this phenomenon. The bubble plume development, and underwater noise spectra, were compared for salty and fresh water. The potential energy of the modeled events resulted in different spectra, and salinity played an essential role in the emitted underwater noise.
    Źródło:
    Hydroacoustics; 2017, 20; 167-172
    1642-1817
    Pojawia się w:
    Hydroacoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-3 z 3

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies