WAVE PATTERNS IN A STREAM AT NEAR-CRITICAL SPEED

Abstract

The two-dimensional free-surface flow generated by a singularity moving with near-critical speed (i.e. with Froude number referred to the water depth near unity) is solved by using the method of matched asymptotic expansions. In the vicinity of the singularity the problem is solved by an infinitesimal wave expansion (inner expansion) while at large distances from the singularity shallow water theory provides the proper solution (outer expansion). A composite expansion provides a uniformly-valid solution for the velocity components, the free-surface profile and the drag force. These two basic approaches of water-wave theory are shown to be solutions of the same flow problem, but valid in different regions. Although the inner expansion satisfies linear equations, the solution depends nonlinearly on the small parameter of the problem (the singularity strength).

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1968
Accession Number
AD0665690

Entities

People

  • G. Dagan

Tags

Communities of Interest

  • Air Platforms
  • Counter WMD
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Abstracts
  • Asymptotic Series
  • Boundaries
  • Complex Variables
  • Computational Fluid Dynamics
  • Computational Science
  • Drag
  • Equations
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Froude Number
  • Hydrodynamics
  • Shallow Water
  • Solitons
  • Water Waves
  • Waves

Fields of Study

  • Mathematics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.