Investigation of the Influence of Rotary Aerodynamics on the Study of High Angleof Attack Dynamics of the F-15B Using Bifurcation Analysis

摘要

The purpose of this research was to use bifurcation analysis to investigate theeffectiveness of rotary balance data in the prediction of aircraft spin behavior as both a stand alone representation of a model's aerodynamic data and in a conventional hybrid model. using the foundation of a previously developed model of the F-15B, the rotary balance aerodynamic force and moment data were implemented as a function of angle of attack, angle of sideslip, non-dimensional rotation steady state rate and the control surface deflections. Bifurcation diagrams were developed as a function of alpha vs. deflection angles of, the rudder, stabilator, and aileron to show highlights of equilibrium and dynamic behavior of the aircraft. For selected configurations, the resulting aircraft state variables showed the rotary balance data model having close correlation to experimental flight test data. Comparison of selected configurations with the hybrid and conventional static and forced oscillation models, showed comparable results. However, the models bifurcation diagrams were very different. Problems were identified with static contributions of the rotary balance data indicating a possible cause. The development of the hybrid model displayed the difficulties in blending of the aerodynamic data in the presence of deficient experimental data or inaccurate data modelling.