PRELIMINARY STUDY OF A ROTOR DRIVEN BY LEADING-EDGE BLOWING

The report summarizes a preliminary experimental study of a new propeller concept. The propeller blades were symmetrical 33-percent-thick air foil sections. Rotational speed was provided by a sheet of air ejected through a spanwise slit cut near the leading edge (Coanda effect). The study was performed at static conditions (zero advance velocity) and at a velocity of advance of 28 fps. At static conditions the 21-in.-diameter rotor produced lift augmentation up to 2.6 and up to 7.95 lb thrust per air horsepower. Lift coefficients of the blades as high as seven were measured. The actual test data yielded a figure of merit of 0.218 max. Upgrading based on limited experimental data indicate that M approx.=0.6 may be attained. At dynamic conditions, this rotor produces higher thrust coefficients and operates at higher advance ratios than a conventional propeller. Thus, a blown foil propeller is capable of generating higher disk loadings while operating at lower rotational speeds. The presently encountered propulsive efficiencies are low, but an extrapolation of data indicates that at least in the range of low advance velocities (at low efficiency regime) the propulsive efficiency of a blown foil propeller may be comparable to that of conventional propeller. (Author)

  • Corporate Authors:

    IIT Research Institute

    10 West 35th Street
    Chicago, IL  United States  60616
  • Authors:
    • Reba, I
  • Publication Date: 1969-1

Media Info

  • Pagination: 61 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00054327
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: Final Rpt
  • Contract Numbers: DOT-7-35512
  • Files: TRIS
  • Created Date: Jun 10 1974 12:00AM