Numerical Investigation of Aerodynamic Loads on a Flexible Wing

In this paper fluid structure interaction of airflow over a flexible wing has been studied. The effect of structural deformity on the aerodynamic load characteristics of a real aero-elastic wing has been quantified in comparison with a rigid wing. The difference between rigid and flexible wing has been analyzed by modelling the flexible wing with deformation data gained form static load test of a supersonic aircraft during design phase. Both rigid and deformed configurations are separately analyzed using CFD techniques. Variation in normal force coefficient and coefficient of pitching moment with angle of attack have been compared and analyzed for the two cases. Additionally, variation in rolling and yawing moment coefficient with side-sip angle have also been compared. It is observed that the normal force coefficient of the deformed wing is slightly more than that of rigid wing, which is attributed to increased wing dihedral of deformed wing. The difference between the load characteristic of both the configurations diminish as the angle of attack in increased. Some difference in the coefficient of pitching moment has also been observed but the trend of both configurations is identical, reflecting that the center of pressure of the wing for both the configurations has not shifted. It is also observed that deflected wing develops an effective dihedral effect that results in increased slope, and hence stability, in rolling moment coefficient.