Rotating Arm Captive Model Tests of the U.S. Coast Guard Prototype 47-FT Motor Lifeboat.

Abstract

The USCG prototype 47-Fr Motor Lifeboat (MLB) experienced transient roll angles of as much as 40 degrees in a turn at 27 knots with 30 degrees of rudder. The prototype was modified to correct this problem, by moving the rudders to a vertical position, vice 15 degrees outboard angle. The tests reported on here were part of an effort to develop a computer simulation of this snap roll phenomenon. Captive rotating arm tests were conducted using a 1/9.032 scale model of the 47 Fr MLB. The model was fully appended, with the propellers driven by an electric motor. Tests were conducted at two speeds, two turning radii, and a range of drift and roll angles. The results are presented in tabular and graphical form. Curves through the data were drawn using a computer plotting package which did not yield the equations for the curves drawn.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1998
Accession Number
ADA358381

Entities

People

  • Edward M. Lewandowski
  • Walter E. Klosinski

Organizations

  • United States Coast Guard Research & Development Center

Tags

Communities of Interest

  • C4I
  • Ground and Sea Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Coast Guard
  • Computer Simulations
  • Coordinate Systems
  • Data Processing
  • Data Reduction
  • Electric Motors
  • Engineering
  • Governments
  • Measurement
  • Model Tests
  • Orientation (Direction)
  • Propeller Shafts
  • Roll
  • Simulations
  • Trim Angle
  • United States
  • United States Government

Readers

  • Aerodynamics/Aeronautics.
  • Electrical Engineering
  • Maritime Security/Maritime Homeland Security