Analysis and numerical computaton of sensitivity derivatives in the transonic regime

Abstract

The incremental iterative technique is implemented to solve the sensitivity equations, and, thus, improve the concept that it is possible to efficiently couple for three dimensional transonic flow about an unswept and twisted rectangular wing an aerodynamic solution for the pressure distribution with a structural solution for the corresponding deflections, and to simultaneously use the quasi-analytical method to obtain the aerodynamic as well as the structural sensitivity derivatives for the fully coupled system. Consequently, due to the improved computational efficiency, the inclusion of other design variables, such as the structural variables to give a total of twelve design variables is possible. Solutions for two structurally different cases are obtained for the same transonic conditions, and a third case considers the effect of the number of points included in determining system sensitivity derivatives. The coupled nature of the aerodynamic-structural system, along with the high non-linearity of the transonic flowfield, yielded results and trends for the discipline and system sensitivity derivatives which differed significantly.