Accession Number:

ADA090051

Title:

The Unified Theory of Ship Motions,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF OCEAN ENGINEERING

Personal Author(s):

• Newman,J. Nicholas
• Sclavounos,P.

Report Date:

1980-08-01

Pagination or Media Count:

24.0

Abstract:

A linear theory is presented for the heave and pitch motions of a slender ship, moving with forward velocity in calm water. The velocity potential includes a particular solution similar to that of the high-frequency strip theory, plus a homogeneous component which accounts for interactions along the length in an analogous manner to the low-frequency ordinary slender body theory. The resulting unified theory is valid more generally for all frequencies of practical importance. Computations are presented for the added-mass and damping coefficients of a floating spheroid, a Series 60 hull, and a frigate. Comparisons with experimental data and with zero-speed exact theories confirm the utility of the unified theory. This theory can be used to analyse the performance of elongated wave-energy absorbers. This application is illustrated for a hinged Cockerell raft.

Descriptors:

• *SHIP MOTION
• PITCH(MOTION)
• SLENDER BODIES
• THEORY
• DAMPING
• SHIP HULLS
• HEAVING

Subject Categories:

• Marine Engineering
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE