Accession Number : AD0779770

Title :   Suppression of Flutter on Interfering Lifting Surfaces by the Use of Active Controls.

Descriptive Note : Scientific rept.,

Corporate Author : TEXAS UNIV AUSTIN DEPT OF AEROSPACE ENGINEERING AND ENGINEERING MECHANICS

Personal Author(s) : Cwach,Emil Ernest ; Stearman,Ronald Oran

Report Date : JAN 1974

Pagination or Media Count : 173

Abstract : An investigation into the possible increase in flutter speed of interfering lifting surfaces by the use of active controls was conducted. The study was designed so that the methods developed to determine the maximum increase in flutter speed could be applied to complex air vehicle configurations throughout the Mach number/altitude range of modern aircraft. The unsteady aerodynamic forces on the lifting surfaces were computed by using doublet lattice aerodynamic computer programs. The structural features of the lifting surfaces were represented by either experimentally measured or analytically computed vibration frequencies and mode shapes. The results of the study indicated that the use of active controls to suppress flutter on interfering lifting surfaces can be more effective than suppressing flutter on isolated surfaces. (Author)

Descriptors :   *Jet aircraft, *Lifting surfaces, *Flutter, Control theory, Spoilers, Boundary layer control, Aerodynamic forces, Feedback, Mathematical models

Subject Categories : Aerodynamics
      Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE