PITCHING MOTIONS OF A MOORED SUBMERGED MINE IN WAVES

Abstract

This report describes a theoretical and experimental investigation of the pitching motions of a moored, submerged mine. The theoretical predictions are based upon linearized-wave theory as well as the assumptions that the body is slender and axisymmetric and is ballasted to be at equilibrium in the horizontal plane. The mooring cable is assumed to be massless and inelastic; the fluid is assumed to be inviscid. The theory results in an equation of undamped motion. Parallel experimental results were obtained on a 2-foot long model in wavelengths ranging from 15 to 55 feet, and these results confirm the theoretical predictions except in the vicinity of resonance, where viscous damping is important. Full-scale predictions are made for the root-mean-square pitching motions in Sea States 4 through 7 for two proposed mine configurations at various depths of submergence. The predicted values are from 1 to 9 degrees in Sea State 4, depending on depth and mine configuration, increasing to greater than 25 degrees in Sea State 7.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1966
Accession Number
AD0632077

Entities

People

  • E. E. Zarnick
  • J. N. Newman
  • P. Plaia

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Buoyancy
  • Cartesian Coordinates
  • Center Of Gravity
  • Coordinate Systems
  • Equations
  • Equations Of Motion
  • Experimental Data
  • Frequency
  • Moment Of Inertia
  • Munitions
  • Ordnance Laboratories
  • Peak Values
  • Probability
  • Slender Bodies
  • Test Sets
  • Waves

Readers

  • Control Systems Engineering.
  • Fluid Dynamics.
  • Marine Hydrodynamics