Development of a Forced Roll Mechanism for Planing Hull Models

Abstract

A Forced Roll Mechanism was designed and built at the Hydromechanics Laboratory at the United States Naval Academy. The FRM was designed as a dynamometer that forces a planing hull model in roll and measures the resulting roll moment as well as the heave and sway forces. The model is fully restrained in all six degrees of freedom. The dynamometer can be configured to either oscillate the model or hold the model at a fixed roll angle, and measure the forces whether dynamic or static in nature, while allowing different testing conditions in terms of speed, rise and trim. The FRM was bench tested using known forces and moments to ensure accuracy and the measured lift forces for zero roll tests were compared with analytical predictions. Initial testing results show that the added inertia hydrodynamic coefficient depends on roll oscillation frequencies for low frequencies. The rig construction and calibration as well as preliminary results are presented.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2012
Accession Number
ADA558365

Entities

People

  • Carolyn Q. Judge
  • William Beaver

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Axial Loads
  • Coefficients
  • Dynamometers
  • Equations
  • Equations Of Motion
  • Frequency
  • Hydrodynamics
  • Instrumentation
  • Load Cells
  • Measurement
  • Measuring Instruments
  • Moment Of Inertia
  • Oscillation
  • Trim Angle
  • United States
  • United States Naval Academy

Readers

  • Computational Modeling and Simulation
  • Marine Hydrodynamics