Automated implementation of a design principle during the optimization of conceptual aircraft

As a powerful numerical technique, optimization has become an inseparable part of aircraft conceptual design, but it has been seldom investigated that how to apply general design knowledge during the automatic process of optimization. This paper presents the approach of implementing a design principle for reducing the directions of radar cross section spikes of military aircraft. Once designer identifies edges in a concept and assigns parallel relations among them with the proposed methods, the relations can be automatically kept according to predefined parameter relationships during optimization, so that each feasible design point can satisfy the principle without "man-in-loop". To validate the effectiveness of the approach, two optimization cases are finally given and discussed.