Within the next few years, numerical shape optimization based on high-fidelity methods is likely to play a strategic role in future aircraft design. In this context, suitable tools have to be developed for solving aerodynamic shape optimization problems, and the adjoint approach—which allows fast and accurate evaluations of the gradients with respect to the design parameters—is proved to be very efficient to eliminate the shock on aircraft wing in transonic flow. However, few applications were presented so far considering other design problems involving 3D viscous flows. This paper describes how the adjoint approach can also help the designer to efficiently reduce the flow separation onset at wing–fuselage intersection and to optimize the slat and flap positions of a 3D high-lift configuration.

On all these cases, the optimizations were successfully performed within a limited number of flow evaluations, emphasizing the benefit of the adjoint approach in aircraft shape design.

This article presented activities carried out at the DLR for the development of the discrete adjoint approaches in the unstructured RANS solver TAU code and its application for solving viscous dominated aerodynamic shape design problems.

Joel Brezillon, Richard P. Dwight (Deutsches Zentrum fu¨r Luft- und Raumfahrt)
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