Modelling of U-tube Tanks for ShipMo3D Ship Motion Predictions

Abstract

Ship roll motions in waves can be significant due to small roll damping and the proximity of ship natural roll frequency to encountered wave frequencies. Roll motions can be reduced by various methods, including bilge keels and active roll stabilization using rudders or dedicated stabilizer fins. U-tube tanks and flume tanks can also be used to reduce roll motions, and have the advantages of being effective at zero ship speed and being protected from environmental hazards such as ice. This report describes the implementation of a U-tube tank model for the ShipMo3D ship motion library. The U-tube tank model has been implemented for computations in both the frequency and time domains. Example computations for a generic frigate demonstrate the reduction of roll motions using a U-tube tank. The relative effectiveness of a U-tube tank will be greatest when a ship has small roll damping, such as a vessel with small or no bilge keels.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2012
Accession Number
ADA604136

Entities

People

  • Kevin Mctaggart

Organizations

  • Defence Research and Development Canada

Tags

DTIC Thesaurus Topics

  • Bilge Keels
  • Bilges
  • Center Of Gravity
  • Coast Guard
  • Computations
  • Coordinate Systems
  • Engineering
  • Frequency
  • Frequency Domain
  • Hard Copy
  • Metacentric Height
  • Military Research
  • Naval Architecture
  • Resonant Frequency
  • Security
  • Ship Motion
  • Time Domain

Readers

  • Aerodynamics/Aeronautics.
  • Naval Architecture and Marine Engineering.
  • Rocket Propulsion.