AN EXPERIMENTAL INVESTIGATION OF THE TURBULENT CHARACTERISTICS OF A BOUNDARY LAYER FLOW OVER A VIBRATING PLATE

Measurements of the spectral density of the axial component of turbulent velocity were made in a boundary layer when the surface beneath it was vibrating in a deterministic manner. These measurements indicated that a narrow-band disturbance resulted from the plate motion. The spectral density of the axial turbulent velocity, at the surface excitation frequency, exhibited a marked increase in magnitude when the surface was being excited. The ratio of the spectral density with and without plate excitation was measured throughout the boundary layer within the region of the vibrating surface. These measurements indicated that the disturbance produced by the surface motion is convected downstream where it is reinforced if it comes into a region which is influenced by a portion of the plate that has an amplitude of vibration greater than the upstream portion. This reinforcement phenomenon was observed for every test condition in which the test plate excitation was a mode where two or more displacement crests appeared in the longitudinal direction. Observations of the transverse variation of the disturbance conclude that there is an absence of any transverse convection nature. ( Author )

• Corporate Authors:

  General Dynamics

  Quincy, MA  United States  02169
• Authors:
  • Izzo, A J
• Publication Date: 1969-5

Media Info

• Pagination: 32 p.

Subject/Index Terms

• TRT Terms: Power spectra; Structural plates; Velocity; Vibration
• Old TRIS Terms: Plate vibration; Velocity fluctuations
• Subject Areas: Design; Environment; Marine Transportation;

Filing Info

• Accession Number: 00002149
• Record Type: Publication
• Source Agency: Defense Documentation Center
• Report/Paper Numbers: U41769049
• Contract Numbers: NONR251200
• Files: TRIS
• Created Date: Oct 30 1972 12:00AM