Waves in Ship Tanks. Part 1. Generating a Random Sea

Abstract

The working fluid in a ship tank in which model ships are tested is the same as the working fluid in the prototype system (the sea) although probably not saline. This implies that equivalence of the Reynolds, Froude, Weber and Mach numbers between model and prototype will not be possible. Gravity waves on water are principally characterised by the Froude number, so the models which are discussed in this paper will be constructed according to Froude's scaling laws. This report discusses in qualitative, and sometimes rather simplified terms, the main difficulties encountered when modelling regular and random long-crested waves in ship tanks. A method for designing an experiment, so that the waves which a model ship encounters have minimum errors in amplitude, has been developed. It is shown that the performance of the beach in a ship tank is of primary importance, and that longer beaches are advantageous if they absorb long waves more effectively. A modification to the equipment employed by civil engineers to test stationary structures in waves is described. The modification enables models in translation to be tested according to the experimental design mentioned above. Great Britain. (EDC)

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1989
Accession Number
ADA215506

Entities

People

  • D. K. Fryer

Organizations

  • Admiralty Research Establishment

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Birds
  • Civil Engineering
  • Computational Science
  • Computer Programs
  • Computers
  • Doppler Effect
  • Engineering
  • Engineers
  • Equations
  • Fluid Mechanics
  • Froude Number
  • Mathematical Filters
  • Measurement
  • Mechanics
  • Signal Generators
  • Spectral Lines
  • Standing Waves

Readers

  • Marine Hydrodynamics
  • Mathematical Modeling and Probability Theory.
  • Systems Analysis and Design