Approximate Evaluation of Added Mass and Damping Coefficients of Two-Dimensional SWATH Sections.

Abstract

Derivation of approximate formulas for determining the added mass and damping coefficients of two-dimensional, small-waterplane-area, twin-hull (SWATH) sections is described. The added mass and damping coefficients of interest are those associated with a forced oscillation of SWATH sections in heave, sway, or roll mode in a free surface. The objective of deriving the approximate formulas for the hydrodynamic coefficients is to simplify the computation of motion of SWATH ships in waves without sacrificing its accuracy significantly. The approximate formulas are derived based on the potential-flow theory. The damping coefficients are obtained in terms of the outgoing wave amplitudes, and the added mass coefficients are obtained by using the damping coefficients through the so-called Kramers-Kronig relations. Within the frequency range of practical interest, the approximate formulas provide satisfactory results. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1978
Accession Number
ADA060839

Entities

People

  • Choung M. Lee

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Amplitude
  • Computations
  • Computer Programs
  • Computers
  • Discontinuities
  • Equations
  • Far Field
  • Fast Fourier Transforms
  • Flow
  • Frequency
  • Integral Equations
  • Integrals
  • Notation
  • Pressure Distribution
  • Swath Ships
  • Test And Evaluation
  • Two Dimensional

Readers

  • Calculus or Mathematical Analysis
  • Marine Hydrodynamics