USING LASERS TO MEASURE FLOW VELOCITIES

For the first time ever, Laser Doppler Velocimetry techniques have been used successfully to measure flow velocities in front of a working propeller at sea in a ship. The equipment to do this was developed at BSRA and the measurements were taken by an Association team on board the 55,000 dwt tanker Scottish Lion during a commercial voyage. Environmental conditions on board ship present serious problems in the application of laser velocimetry techniques. Typical of these are vibration, noise, high humidity levels, restricted space and limited technical back-up facilities. These factors were taken into account in the design and development of the equipment. It must be extremely rugged, relatively unsophisticated yet capable of measuring flow velocities several metres into the water in which no control of the seeding is practicable. The equipment, which was used to measure flow velocities just forward of the propeller, has a photon correlator (by Malvern Instruments Ltd.) as its central data processor and uses a real fringe system in the full back-scatter mode of operation. Measurements up to about four metres from the hull were successfully achieved. Some possible future shipboard applications of the equipment include boundary layer and ship speed measurements. For further information, contact BSRA.

  • Corporate Authors:

    British Ship Research Association

    Wallend Research Station
    Wallsend,   England 
  • Publication Date: 1980-4

Media Info

  • Pagination: p. 7
  • Serial:
    • BSRA News
    • Publisher: British Ship Research Association

Subject/Index Terms

Filing Info

  • Accession Number: 00312481
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 22 1980 12:00AM