APPROXIMATE EVALUATION OF ADDED MASS AND DAMPING COEFFICIENTS OF TWO-DIMENSIONAL SWATH SECTIONS

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 section 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.

  • Corporate Authors:

    David Taylor Naval Ship R&D Center

    Ship Performance Department
    Bethesda, MD  United States  20084
  • Authors:
    • Lee, C M
  • Publication Date: 1978-10

Media Info

  • Features: References;
  • Pagination: 41 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00184185
  • Record Type: Publication
  • Source Agency: David Taylor Naval Ship R&D Center
  • Report/Paper Numbers: DTNSRDC-78/084 Final Rpt.
  • Files: TRIS
  • Created Date: Dec 12 1978 12:00AM