APPARATUS FOR IMPROVING THE OVERALL EFFICIENCY OF A MARINE SCREW PROPELLER

Elongate slots are formed near the leading edges of propeller blades and a supply of polyethylene oxide is ejected through the slots to form a continuous sheet of the polymer flowing on the suction side surface in the region where about 70% of the thrust loading is distributed. The polymer changes the propeller's pressure distribution and increases its lift factor and efficiency. When ejected at a proper flow rate, frictional drag also is reduced. The slots are shaped channels having a particular depth, width and directional orientation that assures the continuity of the flowing sheet. To achieve the benefits, polymer concentration is maintained at a level capable of providing a trailing edge concentration of about 2-20 ppm. (Author)

  • Supplemental Notes:
    • Availability: This Government-owned invention available for U.S. licensing and, possibly, for foreign licensing. Copy of application available NTIS.
  • Corporate Authors:

    Department of the Navy

    The Pentagon
    Washington, DC  USA  20350
  • Authors:
    • Kehman, A F
  • Publication Date: 1979-3-16

Media Info

  • Pagination: 11 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00198810
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: PAT-APPL-6-021 135
  • Files: TRIS
  • Created Date: Oct 17 1979 12:00AM