Global Optimized Shapes of Flying Configurations Compared with Those of Gliding Birds

Abstract

The determination of global optimized (GO) shape of a flying configuration (FC) (namely, the simultaneous optimization of its camber, twist and thickness distributions and also of the similarity parameters of its planform) leads to an enlarged variational problem with free boundaries. An own optimum-optimorum (OO) theory was developed in order to solve this enlarged variational problem. According to this OO theory, a lower limit hypersurface of the drag coefficients of elitary FCs versus the corresponding set of similarity parameters of their planforms is defined. The elitary FCs corresponding to the optimum set of similarity parameters, which is obtained by the numerical determination of the position of the minimum of this hypersurface is, at the same time, the GO FC of the set. The GO shapes of three FCs models were designed by the author according to her OO theory. The transversal cuts of the GO FCs look like those of gliding birds and also their behaviors, by changing of start values of optimization, are similar because nature optimizes too.

Keywords

• Aerodynamical global shape optimization
• Supersonic flow