Several laser beam techniques measuring the velocity profile at the micro-interface between a polymer coated boundary flow and water were investigated. A method based on the Doppler effect of scattered light from trace particles in the fluid was first studied. The spatial resolution of this technique was found to be too poor for the present application. A second method based on the detection through a microscope of the scintillating light from trace particles was also investigated. The microscope was found to be adequate to provide the necessary spatial resolution (within 20mu); however, the light intensity of the scintillating patterns created by a low power laser beam was found to be too weak for detection by a photomultiplier tube. The technique finally adopted was simply to measure the mean elapsed time of illuminated trace particles traveling between two fixed slits placed at the image plane of the eyepiece of the microscope. The spatial resolution of this technique was further improved by focusing the illuminating laser beam to a small width of 20mu. The narrow beam was set parallel to and centered on the objective plane of the microscope. Flow profiles with a spatial resolution of 20mu have been achieved. Some turbulent flow profiles in a pipe are investigated. The existence of a slip layer is positively identified.

  • Corporate Authors:

    American Institute of Aeronautics and Astronautics

    1290 Avenue of the Americas
    New York, NY  United States  10019
  • Authors:
    • Aquino, H
    • Lamontagne, R
  • Publication Date: 1975-1

Media Info

  • Features: References;
  • Pagination: p. 32-35
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00095008
  • Record Type: Publication
  • Source Agency: American Institute of Aeronautics and Astronautics
  • Files: TRIS
  • Created Date: May 7 1975 12:00AM