Experimental investigation and Analysis on aeroelastic performance For aileron reversal and gust Response of a transport aircraft

Abstract

At high cruising speeds airplane wing structures shall experience newlineair loads of significant magnitudes from various directions The flexible wing newlinestructure with an elevated aspect ratio produces the bend twist coupling that newlineis often exceeds the control limits The popular Aeroelastic Control Reversal newline ACR issue occurs because of the unsystematic changes in the aerodynamic newlineQuantities This thesis presents a detailed investigation on the aileron reversal newlineand gust response of a commercial transport airplane that is subjected to a newlinevariety of aerodynamic forces at cruising flight A novel idea is proposed to newlinefind the dynamic stability characteristics of an airplane against the aeroelastic newlinereversal problem The slope of wing lift curve, aileron lift curve and the newlinemoment coefficient concerning to aileron flap deflections are computed using newlinecomputational as well as experimental methods The changes in dynamic newlinepressure distributions about the aileron flap deflection have revealed several newlinefacts to enhance the reversal speed newlineThe atmospheric wind turbulence over a specified time period has a newlinestrong influence on the airplane performance characteristics This unsteady newlineaerodynamic phenomenon is tough to quantify for control systems design and newlinestructural safety Here the load factor enhancement caused by a discrete gust newlinestructure is quantified to ensure the flight safety margin The Kussner newlinefunction is used to find the time variation of the increment of gust dependent newlinelift produced on the aircraft entering a sharp edged gust newline newline