Two-Level Free-Form Deformation for High-Fidelity Aerodynamic Shape Optimization

Abstract

Ag eneral and unif ied geometry framework based on non-uniform rational B-splines is presented. One key aspect of this framework is the use of free-form deformation where the control points defining the geometry itself are embedded rather than the usual surface grid points. This ensures that one maintains an analytical representation of the geometry as it deforms and, if required, also enables the use of an integrated algorithm for mesh movement. The flexibility and robustness of the proposed approach are demonstrated in the context of aerodynamic shape optimization by maximizing, using an Euler-based flow solver and gradient-based optimizer, the lift-to-drag ratio of an initially half-sphere-shaped geometry. Sensitivities are computed analytically via the discrete adjoint method.