Application of Gaussian Wave Packets for Seakeeping Tests of Offshore Structures

  • G. F. Clauss
Part of the NATO ASI Series book series (NSSE, volume 178)

Abstract

For seakeeping tests of offshore structures transient wave techniques are widely used. The method presented here is based on a special Gauss-modulated amplitude spectrum. These wave groups of limited length can be superimposed, the actual surface elevation being a function of packet characteristics and initial time lag.

The application of this technique is demonstrated in two cases presenting a semisubmersible and a crane vessel. It is shown, that a particular problem needs a tailored wave packet containing sufficient energy all over the relevant frequency range. These packets are designed by superimposing individual Gaussian wave groups. The new seakeeping test techniques has the following advantages

  • The wave train is well defined at any location of the tank.

  • The wave elevation and spectrum can be standardized or easily adapted to any specific problem.

  • The duration of the test is very short; reflections (beach) do not interfere the results. At the culmination point the length of the wave train is small. This facilitates short duration seakeeping and manoeuvring tests.

  • The results show high resolution and are in good agreement with regular wave test data.

Summarising, the Gaussian wave packet method is a versatile technique yielding precise and highly resoluted results in a hort time.

Keywords

Wave Packet Wave Train Fourier Spectrum Wave Group Pitch Motion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. /1/.
    Funke, E.R.; Mansard, E.P.D.: A Rationale for the Use of the Deterministic Approach to Laboratory Wave Generation. IAHR-SEMINAR, Lausanne 1987Google Scholar
  2. /2/.
    Clauss, G.F.; Riekert, T.: Generation of Wave Groups for Model Testing and Some Applications in Coastal and Offshore Engineering. 2nd Int. Symp. on Wave Research and Coastal Engineering, University of Hannover, F.R.G., Oct. 12–14, 1988Google Scholar
  3. /3/.
    Coulson, C.A.: Waves, a Mathematical Account of the Common Types of Wave Motion. Oliver and Boyd, Interscience Publ. Inc., NY, 1949Google Scholar
  4. /4/.
    Kinsman, B.: Wind Waves, their Generation and Propagation on the Ocean Surface. Prentice-Hall Inc., Englewood Cliffs, NJ, 1965Google Scholar
  5. /5/.
    Clauss, G.; Bergmann, J.: Gaussian Wave Packets - A New Approach to Seakeeping Tests of Ocean Structures. Applied Ocean Research, Vol. 8, No. 4, 1986Google Scholar
  6. /6/.
    Chakrabarti, S.K.; Libby, A.R.: Further Verification of Gaussian Wave Packets. Applied Ocean Research, Vol. 10, No. 2, pp. 106–108, 1988CrossRefGoogle Scholar
  7. /7/.
    Bergmann, J.: GauBsche Wellenpakete - Ein Verfahren zur Analyse des Seegangsverhaltens meerestechnischer Konstruktionen. PhD Thesis, published at the Institute of Naval Architecture and Ocean Engineering, Technical University Berlin, 1985Google Scholar
  8. /8/.
    Bendat, J.S.; Piersol, A.G.: Random Data. 2nd Edition, New York 1986Google Scholar
  9. /9/.
    Clauss, G.F.: Stability and Dynamics of Semisubmersible After Accidental Damage, 0TC 4729, Houston 1984Google Scholar

Copyright information

© Kluwer Academic Publisher 1990

Authors and Affiliations

  • G. F. Clauss
    • 1
  1. 1.Institut für Schiffs- und MeerestechnikTechnische Universität BerlinBerlin 10Germany

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