Air Gap Prediction for Floating Bodies Using a 3D Numerical Wave Tank Approach

  • Shivaji Ganesan T.Email author
  • Debabrata Sen
Research Article


Computations for air gap response of a semisubmersible platform based on a 3D numerical wave tank approach are presented. The developed method is in time domain and can consider nonlinearities associated with incident wave and hydrostatic forces exactly in determining the body response, but the interaction hydrodynamics of radiation and diffraction are based on simplified linearization assumptions. The incident wave can be defined by any suitable wave theory and here defined by a fully nonlinear numerical wave model. After verifying the present computations results in its degenerated linearized version against the usual linear 3D Green function–based frequency-domain results for air gap predictions, systematic comparative studies are undertaken between linear and the approximate nonlinear solutions. It is found that nonlinear computations can yield considerably conservative predictions as compared to fully linear calculations, amounting to a difference of up to 30%–40% in the minimum air gap in steep ambient incident waves at high and moderate frequencies.


3D numerical wave tank Air gap responses Time-domain approach Numerical wave F–K nonlinear 


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Copyright information

© Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Indian Register of shipping, 52-A, Adi shankaracharya MargMumbaiIndia
  2. 2.Department of Ocean Engineering and Naval ArchitectureIITKharagpurIndia

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