Application of an aeroelastic analysis method for aerodynamic improvement of fighter wings at maneuver flight conditions

Modern fighter aircraft must operate at a wide variety of flight conditions ranging from low-speed flight to transonic and supersonic cruise to transonic maneuver. The maneuvering characteristics of these aircraft is an important consideration when evaluating the overall effectiveness of the vehicle, but typically, these aircraft must be primarily designed to efficiently cruise, since this condition tends to consume the majority of the available fuel. Therefore, efficient design methods are required to optimize the aerodynamic performance of these aircraft at both cruise and maneuver flight conditions.;An aeroelastic analysis method, based on three-dimensional Navier-Stokes equation aerodynamics, has been applied to improve the performance of fighter wings operating at sustained maneuver flight conditions. The scheme reduces the trimmed pressure drag of wings performing sustained high-g maneuvers through a simultaneous application of control surface deflection and aeroelastic twist. The aerodynamic and structural interactions are decoupled by assuming an aeroelastic twist mode shape and optimizing the performance based on this aeroelastic mode. The wing structural stiffness properties are then determined through an inverse scheme based on the aerodynamic loads and desired twist at the maneuver flight condition. The decoupled technique is verified by performing a fully coupled aeroelastic analysis using the maneuver flight conditions and the optimized structural stiffness distributions.;This application uses a high-order numerical aerodynamic analysis method to efficiently define an aeroelastically deflected wing geometry with optimal aerodynamic performance at transonic maneuver flight conditions. In addition, the aerodynamic performance of the wing at cruise conditions is in no way compromised by the application of this scheme. Thus, this method represents a multiple-point wing design capability utilizing computational aerodynamics and aeroelastic tailoring.