Influence of aeroelastic control reversal problem in the airplane lateral stability modes

Abstract

At high-cruising speeds, airplane wing structures shall experience air loads of significant magnitudes from different directions. The flexible wing structure with an elevated aspect ratio produces the bend-twist coupling that often exceeds the control limits. The popular aeroelastic control reversal issue occurs because of the unsystematic changes in the aerodynamic quantities. This article presents a detailed investigation on the airplane lateral stability that is subjected to a variety of aerodynamic forces at cruising flight. A novel idea is proposed to find the dynamic stability characteristics of an airplane against the aeroelastic reversal problem. Initially, the pitching moment relating to the change in lift at various angles of attack with longitudinal static stability condition is verified by using computer simulation. Then the slope of wing lift curve, aileron lift curve and the moment coefficient concerning to aileron deflection are computed using computational as well as experimental methods. The changes in pressure distributions about the aileron deflection revealed several facts to enhance the reversal speed. The wind tunnel testing results are perfectly concur with the computational fluid dynamics plots. The outcome of experimental analysis is confirming that aeroelastic control reversal speed enhancement without any major structural optimization is possible. The aeroelastic behaviour of large commercial airplanes and subsonic bombers are the primary interest in the view of application about this analysis.