FLOW CONTROL OF CENTRIFUGAL JET-FLAP BLOWERS FOR AIR CUSHION VEHICLES

Air-cushion vehicles and surface-effect ships may require some form of dynamic lifting air control. An experimental investigation was carried out to demonstrate both the steady-state and the dynamic flow control characteristics at constant pressure of a model (32.7 in. diameter) double-inlet, double-width centrifugal blower at low tip speed (approximately 250 ft/s). The impeller was designed with fixed backward-curved jet-flap airfoil blades and the housing was equipped with rotatable jet-flap inlet guidevanes. The flow control test was carried out at constant pressure, starting from the maximum efficiency (85%) point of the basic blower. Over 50% negative flow control was achieved with the jet-flap inlet guidevanes and 50% positive flow control was obtained with the impeller jet-flap, with a jet-flap supply flow of only 2.8%. Frequency response tests were carried out on the impeller jet-flap flow control system with a rotating butterfly. The pressure amplitude ratio was found to remain above-3 dB for all frequencies tested, up to the maximum 12.5 Hz, where the phase angle approached 90 deg.

  • Supplemental Notes:
    • Paper presented at the AIAA/SNAME Advanced Marine Vehicles Conference, Baltimore, 2-4 October 1979.
  • Corporate Authors:

    American Institute of Aeronautics and Astronautics

    1290 Avenue of the Americas
    New York, NY  USA  10019
  • Authors:
    • Goldschmied, F R
  • Publication Date: 1980-4

Media Info

  • Features: References;
  • Pagination: p. 48-55
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00316642
  • Record Type: Publication
  • Report/Paper Numbers: Article 79-2006R
  • Files: TRIS
  • Created Date: Sep 16 1980 12:00AM