ON THE FUTURE OF TRANSONIC FLIGHTS: CURVED PLANFORM WINGS FOR BUFFET-ONSET CONTROL

The results of studies on a curved planform wing are discussed: these studies consist of three-dimensional unsteady Computational Fluid Dynamics analyses. To test the calculation reliability, two-dimensional analyses carried out on a profile, highlighted the capability of standard unsteady aerodynamics methodologies to simulate transonic flows and to estimate the buffet boundary. To this end, a comparison was made with the results available in the literature, obtaining that the results presented here are in good agreement with the experimental data. This fact can be considered as a preliminary confirmation of the reliability of the adopted calculation method. The numerical analyses show that the curved wing configuration allows an important reduction in aerodynamic resistance, especially in the transonic regime, influencing the non-linear effects typical of transonic aerodynamics. The condition of aeroelastic instability of the curved wing, a classic bending-torsion flutter, is postponed compared to the flutter-buffet of a conventional swept wing. The reduction in aerodynamic drag and the increase in the stability margin have the beneficial effect of reducing emissions of polluting gases and can technically lead to a reduction in the weight of transport aircraft. A comparison of the transonic flow structure between a conventional swept wing and a curved planform wing shows the potential characteristics of the proposed wing configuration in view of a technical application for the next generation aircrafts.