Solving the linearized forward-speed radiation problem using a high-order finite difference method on overlapping grids

Research output: Contribution to journalJournal articleResearchpeer-review

93 Downloads (Pure)

Abstract

The linearized potential flow approximation for the forward speed radiation problem is solved in the time domain using a high-order finite difference method. The finite-difference discretization is developed on overlapping, curvilinear body-fitted grids. To ensure numerical stability, the convective derivatives in the free-surface boundary conditions are treated using an upwind-biased stencil. Instead of solving for the radiation impulse response functions, a pseudo-impulsive Gaussian type displacement is employed in order to tailor the frequency-content to the discrete spatial resolution. Frequency-domain results are then obtained from a Fourier transform of the force and motion signals. In order to make a robust Fourier transform, and capture the response around the critical frequency, the tail of the force signal is asymptotically extrapolated assuming a linear decay rate. Fourth-order convergence of the calculations on simple geometries is demonstrated, along with a nearly linear scaling of the solution effort with increasing grid resolution. The code is validated by comparison with analytical and semi-analytical solutions using submerged and floating closed-form geometries. Calculations are also made for a modern bulk carrier, and good agreement is found with experimental measurements.
Original languageEnglish
JournalApplied Ocean Research
Volume69
Pages (from-to)220–244
ISSN0141-1187
DOIs
Publication statusPublished - 2017

Keywords

  • Forward-speed radiation
  • Double-body
  • Generalized m-terms
  • Finite difference
  • Overlapping grids

Fingerprint

Dive into the research topics of 'Solving the linearized forward-speed radiation problem using a high-order finite difference method on overlapping grids'. Together they form a unique fingerprint.

Cite this