Parametric Studies of Transonic Aeroelastic Effects of an Aircraft Wing/Tip Store

Abstract

This research investigates the effect of store parameters variation on store-induced flutter and limit-cycle oscillation phenomena of an aircraft wing in the transonic regime. The primary store parameters were its mass and the chordwise location of its center of gravity. The effect of including store aerodynamics on the wing/tip store configuration was also investigated. The tip store center of gravity (c.g.) was varied and positioned at three different locations: 32.5, 40, and 50%, with respect to aerodynamic tip chord. Automated Structural Optimization System and Computational Aeroelasticity Program‐Transonic Small Disturbance were used in the linear and nonlinear region to perform this research. Studies showed that flutter speed increases as the store c.g. was moved forward toward the leading edge. This gives an indication that store c.g. must be placed as far forward as possible with respect to the elastic axis to delay the occurrence of flutter, while satisfying other design constraints. It was observed that the increase in tip store mass significantly reduced the flight operating speed range of the aircraft. The effect of inclusion of store aerodynamics for different wing/store configurations was found to be insignificant compared to their corresponding mass-only models in the transonic regime. The limit-cycle oscillation (LCO) onset speed was found to be sensitive to both store mass and store c.g. parameters and varied significantly for different store mass configurations. The LCO onset speed decreased significantly with increase in store mass and aft movement of store c.g.