A Computerized Hot-Wire Investigation of the Stability of Separated Shear Layers with Application to Ship Silencing.

Abstract

This study was made of the stability of a two-dimensional air jet applicable to ships' noise silencing. The initially laminar flow was excited using sound from a loudspeaker. Due to the instability of the free boundary layers, the initial disturbance caused by sound pressure was found to be amplified exponentially. The laminar flow was found to turn turbulent at a downstream distance of approximately five jet widths. At this distance the amplification rate of the disturbance became less than exponential. Use was made of a new computer-assisted hot wire technique. The procedures and results are included in the paper. The results of this study are applicable to studies of flow induced cavity resonance, which is a major cause of sonar self-noise and of vibrations in ships and aircraft. (Author)

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Document Details

Document Type
Technical Report
Publication Date
May 23, 1977
Accession Number
ADA045377

Entities

People

  • David Michael Schubert

Organizations

  • United States Naval Academy

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustics
  • Aircrafts
  • Boundary Layer
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Frequency
  • Hot Wire
  • Measurement
  • Mechanics
  • Phase Velocity
  • Sound Pressure
  • Speed
  • Turbulent Flow
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Engineering
  • Physics

Readers

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