DLR TRANSONIC INVERSE DESIGN CODE, EXTENSIONS AND MODIFICATIONS TO INCREASE VERSATILITY AND ROBUSTNESS

Kurzfassung

In recent years the DLR inverse design code has often been used to design wings for transonic transport aircraft. The DLR inverse design code computes the wing geometry for a prescribed target pressure distribution. It is based on the numerical solution of the integral inverse transonic small perturbation (TSP) equations. New applications and configurations have shown limitations and possibilities of extension of the inverse design code. In this work we present several extensions and modifications of the inverse design code. The first modification concerns applications for high transonic Mach numbers or cases with strong shocks. The introduced modifications allow to obtain converged design solutions for cases were the original method failed. The second modification is the extension of the code to general non-planar wings. Previously the design code was restricted to non-planar wing designs with small dihedral or to nacelle design. A third modification concerns airfoil/wings designed for wind tunnel design. In order to design a swept wing between two wind tunnel walls the solution method of the inverse TSP equations was extended to two symmetry planes. The introduced extensions and modifications have increased the robustness and range of applicability of the inverse design code. The required modifications in the numerical solution method of the TSP equation are described and results are validated with corresponding redesign test cases.