Download or read book Wind-tunnel Investigation of Effect of Sweep on Rolling Derivatives at Angles of Attack Up to 13© and at High Subsonic Mach Numbers, Including a Semiempirical Method of Estimating the Rolling Derivatives written by James W. Wiggins and published by . This book was released on 1954 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was performed in the Langley high-speed 7- by 10-foot tunnel in order to determine the rolling derivatives for swept-wing-body configurations at angles of attack from 0 degrees to 13 degrees and at high subsonic Mach numbers. The wings had sweep angles of 3.6 degrees, 32.6 degrees, 45 degrees, and 60 degrees at the quarter-chord line, an aspect ratio of 4, a taper ratio of 0.6, and an NACA 65A006 airfoil section parallel to the free stream. The results indicate a reduction in the damping-in-roll derivative at the higher test angles of attack. Of the wings tested, instability of the damping-in-roll derivative was experienced over the largest ranges of angle of attack and Mach number for the 32.6 sweptback wing.