Accession Number:

ADA167697

Title:

Application of Bifurcation and Catastrophe Theories to Near Stall Flight Mechanics.

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1985-01-01

Pagination or Media Count:

247.0

Abstract:

This thesis sought to develop nonlinear systems analysis techniques capable of analyzing and predicting the complex behavior found in high-angle-of-attack flight. The primary research method involved calculation of equilibrium surfaces where the time rate of change of each of the state variables is set to zero in the aircraft equations of motion, and the states that will satisfy that condition are found for various control deflections. The equilibrium surfaces were calculated numerically through use of continuation methods. An equilibrium trajectory analysis of a fifth order model of the aircraft showed significant adverse yaw problems at high AOA as well as the presence of roll coupling. Bifurcational behavior was found in the same fifth order model and verified by previous research. A mechanism for transfer of kinetic energy during the catastrophic behavior shown is hypothesized. A spin equilibrium surface for the aircraft was determined from an eighth order model and, from that surface, possible control deflections for recovery from the spin were obtained.

Subject Categories:

  • Numerical Mathematics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE