Static Aeroelasticity and Stability of Very Flexible Swept Wings
Bar Revivo, Daniella E. Raveh
Abstract
The study investigates the aeroelastic behavior of very flexible, swept-back wings through computational analyses and comparisons with straight-wing models. Using the Pazy wing as a benchmark, the study evaluates how large deformations and varying sweep angles affect the static aeroelastic response, natural frequencies, mode shapes, and flutter characteristics. The Modal Rotation Method (MRM) and Nastran software are employed to conduct static, free-vibration, and flutter analyses under various airspeeds and angles of attack. The findings show how bending-torsion coupling in swept wings, which exists even in their undeformed states, affects the stability and static behavior compared to straight wings. Wing deformation decreases flutter onset speeds, with stronger effects at lower sweep angles. Static aeroelastic analyses indicate that the strip aerodynamic model, which assumes undeformed lift-line slopes, may not be adequate for accurate swept-wing deformation predictions. The study highlights the need for nonlinear structural modeling and high-fidelity aerodynamic modeling in flexible swept wings and suggests further experimental validation for improved aeroelastic performance predictions.