Abstract
In this article, a drag breakdown approach is introduced which can decompose the aerodynamic drag of aircraft into physical drag components of wave, viscous and induced drag. In aerodynamic shape optimization problems, this approach allows to analyze drag reduction effect quantitatively, and to visualize drag source distribution in its flow-field intuitively. The drag breakdown approach is applied in aerodynamic shape optimization problems of two-dimensional airfoil as well as of wingtip device of a conventional transonic aircraft model, and then its effectiveness is clearly demonstrated. The visualization of design variables space and the extraction of engineering design knowledge by using the drag breakdown approach and a response surface model approach are also introduced in this article.
