AUTOROTATING WINGS: AN EXPERIMENTAL INVESTIGATION.

Abstract

The autorotation of a flat plate about its spanwise axis was experimentally studied. Most of the work was done with a model mounted on air bearings in a wind tunnel. The flow pattern differed from that over a static wing. The wing did not stall until it was almost perpendicular to the free stream. At Re = 240,000, the maximum lift coefficient was 4.50, with an average value of 2.20, while the maximum drag coefficient was 4.30 with an average value of 1.60. The angular acceleration was small; the wing rotated at an almost constant angular velocity. The wing nondimensional rotation rate approached an asymptotic limit at 0.35. Applying a driving torque to the wing increased the lift and drag, while a retarding torque reduced them. A variety of wing configurations were tested, with no major changes in the autorotation phenomenon. Freely falling wings were studied and behaved in a manner similar to the fixed axis wings for comparable Reynolds numbers. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1970
Accession Number
AD0710288

Entities

People

  • Edmund H. Smith

Organizations

  • University of Michigan

Tags

DTIC Thesaurus Topics

  • Angular Acceleration
  • Autorotation
  • Bearings
  • Coefficients
  • Flow
  • Free Stream
  • Gas Bearings
  • Motion
  • Physical Properties
  • Reynolds Number
  • Rotation
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.