A COMPUTERIZED HOT-WIRE INVESTIGATION OF THE STABILITY OF SEPARATED SHEAR LAYERS WITH APPLICATION TO SHIP SILENCING

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)

• Corporate Authors:

  United States Naval Academy

  ,    
• Authors:
  • Schubert, D M
• Publication Date: 1977-5-23

Media Info

• Pagination: 90 p.

Subject/Index Terms

• TRT Terms: Aerodynamics; Anemometers; Anemometry; Boundary layer; Boundary layer separation; Information processing; Laminar flow; Noise; Noise control; Ships
• Uncontrolled Terms: Injection; Noise reduction; Ship noise
• Old TRIS Terms: Aerodynamic characteristics; Boundary layer stability; Hot wire anemometers; Hot wire anemometry; Laminar boundary layer
• Subject Areas: Environment; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00169356
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: USNA-TSPR-89 Final Rpt.
• Files: TRIS
• Created Date: Mar 14 1978 12:00AM