Determination of non-linear damping coefficients of bottom-hinged oscillating wave surge converters using numerical free decay tests

H. Asmuth, P. Schmitt, B. Elsaesser, A. Henry

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    3 Citations (Scopus)

    Abstract

    Linear wave theory models are commonly applied to predict the performance of bottom-hinged Oscillating Wave Surge Converters (OWSC) in operational sea states. To account for non-linear effects, the additional input of coefficients not included in the model itself becomes necessary. In ocean engineering it is common practice to obtain damping coefficients of floating structures from free decay tests. This paper presents results obtained from experimental tank tests and numerical computational fluid dynamics simulations of OWSC’s. Agreement between numerical and experimental methods is found to be very good, with CFD providing more data points at small amplitude rotations. Analysis of the obtained data reveals that linear quadratic-damping, as commonly used in time domain models, is not able to accurately model the occurring damping over the whole regime of rotation amplitudes. The authors conclude that a hyperbolic function is most suitable to express the instantaneous damping ratio over the rotation amplitude and would be the best choice to be used in coefficient based time domain models.

    Original languageEnglish
    Title of host publicationRenewable Energies Offshore - 1st International Conference on Renewable Energies Offshore, RENEW 2014
    EditorsC. Guedes Soares
    PublisherCRC Press/Balkema
    Pages507-513
    Number of pages7
    ISBN (Print)9781138028715
    Publication statusPublished - 01 Jan 2015
    Event1st International Conference on Renewable Energies Offshore, RENEW 2014 - Lisbon, Portugal
    Duration: 24 Nov 201426 Nov 2014

    Conference

    Conference1st International Conference on Renewable Energies Offshore, RENEW 2014
    CountryPortugal
    CityLisbon
    Period24/11/201426/11/2014

    ASJC Scopus subject areas

    • Engineering(all)

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  • Cite this

    Asmuth, H., Schmitt, P., Elsaesser, B., & Henry, A. (2015). Determination of non-linear damping coefficients of bottom-hinged oscillating wave surge converters using numerical free decay tests. In C. G. Soares (Ed.), Renewable Energies Offshore - 1st International Conference on Renewable Energies Offshore, RENEW 2014 (pp. 507-513). CRC Press/Balkema.