Accession Number : AD0710288

Title :   AUTOROTATING WINGS: AN EXPERIMENTAL INVESTIGATION.

Descriptive Note : Interim technical rept.,

Corporate Author : MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING

Personal Author(s) : Smith,Edmund H.

Report Date : JUL 1970

Pagination or Media Count : 156

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)

Descriptors :   (*WINGS, *AUTOROTATION), FLAT PLATE MODELS, STALLING, LIFT, DRAG, REYNOLDS NUMBER, AERODYNAMIC CHARACTERISTICS

Subject Categories : Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE