DEFINITION:

The main objective of the wing design is the minimisation of the drag in cruise conditions :

• Lift induced drag, through appropriate platform, twist design or through wing tip devices (winglet, wing tip sail, tip turbine,?);
• viscous drag, through airfoil section shaping to avoid separation of turbulent boundary layer;
• Shock wave drag, controlled in order to prevent strong interaction with boundary layer (no separation).

On the other hand, improvements are searched on aerodynamic interactions, in particular wing-body, propulsion installation and static margin in order to reduce the trim drag.

The wing design uses the last improvements of CFD with numerical optimisation tools and now some multidisciplinary constraints are included in the process.

For the design of flexible wing like rotorcraft blade, coupling methods are used where structural deformations are taken in account. In some cases acoustic constraints are also introduced.

On missiles, the design of control surfaces is mainly driven by hinge moment constraint.

(Source: ACARE Domain 106)