Effect of Wing Geometric Parameters on Flutter Speed

Abstract

Fluid-Structure Interaction (FSI) of an aircraft wing is given much importance in recent days due to safety in operation while reducing structural weight of the wing. Any design modification or newer design of an aircraft is expected to have improvements in overall performance. The geometric variation of the wing for aerodynamic performance is given importance before considering it for any major changes. It is important to know the effect of wing modification on flutter speed. Analytical and semi-empirical tools were developed in earlier days to estimate the flutter speed. Currently, coupled Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) simulations are possible due to development in numerical methods and availability of increased computing power. Ansys-Multi Field Solver is used in this study. A well-known AGARD 445.6 wing geometry is considered for transonic Mach number of 0.901. The predicted onset flutter speed, 297m/s, has shown good agreement with the experimental data. A parametric study on reduction of 10% wing thickness predicted 1% reduction in flutter speed and increase of 10% wing thickness predicted, 5% more on flutter speed. Increase in wingspan by 10% has predicted reduction on the flutter speed of 2% and decrease in wingspan by 10% has predicted increased flutter speed by 5%. Increase in wing sweep by 10% increases flutter speed by 2% and reduction in sweep by 10% has decreased flutter speed by 5%.