During different flight conditions - such as landing, cruising, etc. - airplane wings have to satisfy different requirements. The design of the wings is a compromise since there is not a single design, which would yield optimal performance for different flight conditions. Hence, the wings are designed to be able to adapt their geometry according to varying conditions. Currently, this adaptation of the wings is realized by the displacement of some discrete components such as flaps, although they exhibit suboptimal performance. Alternatively, this adaptation can be achieved by the wing morphing technique. This technique removes the gaps between the stationary and movable components, and also has significant advantages on performance, since it eliminates aerodynamic losses due to these gaps. In addition, this technique offers more degrees of freedom to adapt the wing shape, and consequently better optimal performance for a wider range of flight conditions. The wing morphing technique can be implemented by replacing conventional wing ribs with compliant structures, which leads to lightweight designs with less mechanical parts. The design of compliant structures determines the deformation of the wing under applied actuator loads. This deformed form of the wing has to meet the requirements of specific flight conditions. Therefore, the optimization of compliant structures is essential to satisfy these requirements. In this thesis, a gradient based shape optimization framework has been developed within the Kratos Multi-Physics environment. By using this framework, a node-based shape optimization has been performed for a chosen compliant structure design. The objective of this optimization is to reduce the drag or maximize the lift-drag ratio of the airfoil in deformed (actuated) form for a specific flight condition. Hence, the optimization problem involves the shape sensitivities from the fluid part, as well as the structural sensitivities. The framework combines different solvers and applications in the Kratos Multi-Physics environment to obtain these sensitivities from different fields. The verification and the code implementation is done only for the structural adjoint sensitivities. In the node-based shape optimization, the Vertex Morphing technique is used as the sensitivity filtering technique, and the steepest descent algorithm is used with a constant step size as the optimization algorithm. Therefore, the effect of different filter radiuses and step sizes are studied. In conclusion, it is observed that significant improvements can be achieved by performing the shape optimization, and the achieved improvements with the resulting designs are presented for different compliant structures.     «

During different flight conditions - such as landing, cruising, etc. - airplane wings have to satisfy different requirements. The design of the wings is a compromise since there is not a single design, which would yield optimal performance for different flight conditions. Hence, the wings are designed to be able to adapt their geometry according to varying conditions. Currently, this adaptation of the wings is realized by the displacement of some discrete components such as flaps, although...     »