Two theoretical methods for helicopter rotors or propellers in subsonic flow are presented, namely a lifting-line theory for a helicopter rotor in vertical climb, hovering or in slow descent, or a propeller in steady forward flight or operating statically, and a disk approximation for a helicopter rotor in forward flight or a propeller in yaw. In both methods, the compressibility of the air is taken into account. First, the problem of a vertically moving rotor is treated with the method of matched asymptotic expansions. In the second case, the rotor is approximated by a disk of continuous thrust and in-plane force distributions, which are assumed to be known. Its wake is represented by a semi-infinite cylinder of distributed vorticity. Formulas for the induced velocity field are derived.

  • Corporate Authors:

    Pergamon Press, Incorporated

    Maxwell House, Fairview Park
    Elmsford, NY  United States  10523
  • Authors:
    • Johansson, BCA
  • Publication Date: 1978

Media Info

  • Features: References;
  • Pagination: p. 1-9
  • Serial:
    • Vertica
    • Volume: 2
    • Issue Number: 1
    • Publisher: Pergamon Press, Incorporated

Subject/Index Terms

Filing Info

  • Accession Number: 00188569
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Mar 14 1979 12:00AM