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.
David Taylor Naval Ship R&D CenterShip Performance Department
Bethesda, MD United States 20084
- Lee, C M
- Publication Date: 1978-10
- Features: References;
- Pagination: 41 p.
- TRT Terms: Coefficients; Computer programs; Damping (Engineering); Damping (Physics); Force; Hydrodynamics; Mass; Rolling; Seakeeping; Ship motion; SWATH ships; Two dimensional flow; Waves
- Uncontrolled Terms: Heaving
- Old TRIS Terms: Added mass; Heave damping; Roll damping; Wave forces on structures
- Subject Areas: Hydraulics and Hydrology; Marine Transportation; Vehicles and Equipment;
- 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