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A low-computational-cost method is proposed in this paper to predict steady-state nonlinear aeroelastic response for high-aspect-ratio wings. This fast nonlinear static aeroelasticity method relies on a simple but robust mathematical approach. The work presented in this paper evaluates the accuracy of a nonlinear aerodynamic method on a large range of Mach numbers for a geometry representative of a typical industrial high-aspect-ratio-wing aircraft. The robustness of the method relies on the accurate estimation of the local pressure field based on an aerodynamic database using a local incidence estimated with a vortex lattice method. The database can be filled with flight test, wind tunnel test, or high-fidelity numerical simulation. The structural deformation is provided by a coupled aeroelastic high-fidelity numerical simulation, and so this paper focuses mainly on the development and validation of the aerodynamic model. Then, the flexible coefficients of the wing are compared to the high-fidelity aeroelastic numerical simulations for a set of Mach numbers ranging from subsonic to transonic conditions. The results presented in this paper show that the present method is very accurate for low-Mach-number regimes (error is lower than 1% on lift), and it is also adapted to transonic flow regimes because the error on lift is lower than 5%. For high Mach numbers, the current solution commits larger errors on drag and pitching moment coefficients.

International audience; A low-computational-cost method is proposed in this paper to predict steady-state nonlinear aeroelastic response for high-aspect-ratio wings. This fast nonlinear static aeroelasticity method relies on a simple but robust mathematical approach. The work presented in this paper evaluates the accuracy of a nonlinear aerodynamic method on a large range of Mach numbers for a geometry representative of a typical industrial high-aspect-ratio-wing aircraft. The robustness of the method relies on the accurate estimation of the local pressure field based on an aerodynamic database using a local incidence estimated with a vortex lattice method. The database can be filled with flight test, wind tunnel test, or high-fidelity numerical simulation. The structural deformation is provided by a coupled aeroelastic high-fidelity numerical simulation, and so this paper focuses mainly on the development and validation of the aerodynamic model. Then, the flexible coefficients of the wing are compared to the high-fidelity aeroelastic numerical simulations for a set of Mach numbers ranging from subsonic to transonic conditions. The results presented in this paper show that the present method is very accurate for low-Mach-number regimes (error is lower than 1% on lift), and it is also adapted to transonic flow regimes because the error on lift is lower than 5%. For high Mach numbers, the current solution commits larger errors on drag and pitching moment coefficients.

International audience; Aeroelasticity plays an important role in the design and certification of aircrafts. Whether steady aerodynamics is key for static methods, unsteady phenomenon is key for dynamic approaches. Nevertheless, in both aeroelastic problematics, it is basically aerodynamics who monopolizes the CPU cost. Thus, fast methods are interesting as alternative to the high cost of CFDCSM simulations.The aim of this study is to present an unsteady method that predicts the aerodynamics of aircrafts encountering a wind gust. First of all, the process that brought to the formulation of the static aeroelasticity from Wind Tunnel Tests (WTT) is refreshed. It is a rapid and robust method based on the principle of the local incidence shift due to flexible effects. This difference in the angle of attack is used to interpolate the pressure coefficient from aerodynamics lookup tables.Secondly, the static method (called Fast Nonlinear Static Aeroelasticity –FNSA–) is validated when analyzing a high aspect ratio wing which assures a flexible structure. The method deals with nonlinear, flexible and compressible effects in steady aerodynamics.Finally, an algorithm is proposed to integrate the FNSA formulation to the unsteady problem of gust load computation. The methodology uses a quasi-steady approach of the static solver together with Wagner delay function modeling the unsteadiness of the flow. Restricting our aeroelastic equation of motion to a simple mass-stiffness system, the airstream directed downward due to the gust is added to the downwash of each section. The formulation allows, then, a reaction to the gust at each time step that yields to flexible results with an accuracy comparable to the Unsteady Vortex Lattice Method but around 3600 times faster.

International audience

Realització d’un estudi sobre les metodologies de fabricació d’una estructura monocasc i fabricació d’espècimens que permetin avaluar la viabilitat de la producció i el comportament de les peces Recopilació d’informació sobre mètodes i alternatives per a la fabricació: materials, procediments de fabricació i post-processos. Es definiran les especificacions de l’estructura i s’avaluarà la millor metodologia de fabricació. Es procedirà a fabricar un prototip i es definiran els assajos per validar la qualitat de la solució.