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Virginia Tech

Full Scale Investigation of Bilge Keel Effectiveness at Forward Speed

Abstract

dc:description.abstract

Ship motions in a seaway have long been of great importance, and today with advanced hull forms and higher speeds they are as important as ever. While one can now often adequately predict heave, pitch, sway, yaw and even surge, roll motions are much more difficult. Roll is the one motion that is very dependent upon viscous effects of the fluid. Recently, at David Taylor Model Basin, there have been model experiments where the bilge keels were instrumented in order to directly measure their damping force upon the vessel. To build upon this work and to validate it when applied to full scale vessels, a trial using the Italian naval vessel Nave Bettica was performed. The objective of this thesis is to describe the experiment, present and analyze the results, and offer some conclusions based upon these results. The process of instrumenting the port bilge keel using strain gages and correlating their output to pressures and total forces is described. Selected results for different forward speeds are presented, with full results in the appendices. Particle image velocimetry (PIV) was also performed during the test and was used to measure the flow field in a three foot by three foot area under the aft end of the same bilge keel. Selected image series are presented, as is a methodology for using these images to calculate the center of pressure and the corresponding results.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Aerospace and Ocean Engineering
Department dc:contributor.department
Aerospace and Ocean Engineering
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2008

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Grant, David J.
Chair dc:contributor.committeechair
  • McCue-Weil, Leigh S.
Committee members dc:contributor.committeemember
  • Etebari, Ali
  • Hughes, Owen F.

Subjects

dc:subject × 3

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
etd-05072008-133744
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/32322

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Grant, David J.. Full Scale Investigation of Bilge Keel Effectiveness at Forward Speed. masters thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32322