USE OF AERODYNAMIC PARAMETERS FROM NONLINEAR THEORY IN MODIFIED-STRIP-ANALYSIS FLUTTER CALCULATIONS FOR FINITE-SPAN WINGS AT SUPERSONIC SPEEDS

摘要

The flutter characteristics for two untapered wings, one having 150 sweep and aspect ratio 5.34, the other having 30° sweep and aspect ratio 4.16, have been investigated analytically for Mach numbers up to 3.0. The calculations were based on the modified-strip-analysis method of NACA Research Memorandum L57L10 with the required aerodynamic parameters computed from linear theory, from shock-expansion theory, and from Busemann second-order theory. The results were com¬pared with flutter experiments over the Mach number range. Supersonic flutter speeds were satisfactorily predicted by the modified strip analysis employing aerodynamic parameters computed from the nonlinear theories but were high when supersonic linear theory was used. Flutter speeds calculated for subsonic Mach numbers by use of linear-theory aerodynamic parameters were in good agreement with experimental values.