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    Item type:Publication, Access status: without files ,
    Experimental and numerical advances in underwater radiated noise prediction of cavitating propeller-hull combinations
    (International Commission for Acoustics (ICA), 2022-06)
    Kimmerl, Julian
    ;
    Mertes, Paul
    ;
    Krasilnikov, Vladimir
    ;
    Koushan, Kourosh
    ;
    Savio, Luca
    Propeller induced cavitation is the primary underwater radiated noise source of motorized shipping activities, which coincides with acoustic frequencies utilized by marine life and may therefore have negative impacts on the ecosystem. This paper is the conclusion of the research project ProNoVi introduced at ICA2019 and presents the final results of both experimental and numerical campaigns on a high-level for all participants. While propulsion related phenomena are analyzed based on evaluation of high-speed recordings, the focus lies on model and full scale comparisons of acoustic measurements with pressure pick-ups and hydrophones in the far-field. Accompanying simulations with active phase transition are undertaken, by employing high fidelity CFD methods with RANS and scale resolved DES or LES turbulence modelling. For different methods and setups, the emitted noise from the propeller and its slipstream, where induced vorticity and cavitation-dynamics play an important role, are compared for an openwater propeller case and several propeller-hull combinations. The analysis of these workflows on real propeller-ship combinations reveal adequate results, regarding comparability and reproducibility between different experimental and numerical setups and point to future opportunities for the improvement of accurate underwater noise predictions while saving numerical and experimental resources.
    Publicationtype: Conference Paper
      81
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    Item type:Publication, Access status: without files ,
    Analysis Methods and Design Measures for the Reduction of Noise and Vibration Induced by Marine Propellers
    (Deutsche Gesellschaft für Akustik, 2019-09)
    Kimmerl, Julian
    ;
    Mertes, Paul
    ;
    Krasilnikov, Vladimir
    ;
    Koushan, Kourosh
    ;
    Savio, Luca
    The paper presents the ongoing work in the research project ProNoVi. The objective of the project is to improve the numerical and experimental methods for the prediction of noise and vibrations induced by a propeller operating behind ship hull in full-scale conditions. Based on the improved methods practical recommendations for the reduction of noise and vibration levels for diơerent classes of vessels are a further objective. The propeller cavitation noise is identified as the dominating noise source, which coincides with important frequencies of perception of marine fauna and thus may have negative impact on marine life. As a side eơect, reducing the noise under water will increase comfort and thus safety for crew and passengers on board. The project aims at delivering a better understanding of fundamental physical mechanisms related to turbulence, induced vorticity and cavitation dynamics, which play a decisive role in generation of tonal and broadband propeller noise. The project partners will give a joint presentation, focusing on state-of-the-art in the field, today’s challenges in both the experimental and numerical approaches, and how the ProNoVi project is addressing those. ProNoVi is funded by the European Union. Further information is available at www.martera.eu/projects/pronovi.
    Publicationtype: Conference Paper
      95