Buffet-Onset Constraint Formulation for Aerodynamic Shape Optimization
G. K. W. Kenway, and J. R. R. A. Martins
AIAA Journal, 55(6):1930–1947, 2017
High-fidelity computational modeling and optimization of aircraft configurations have the potential to enable engineers to create more efficient designs that require fewer unforeseen modifications late in the design process. Although aerodynamic shape optimization has the potential to produce high-performance transonic wing designs, these designs remain susceptible to buffet. To address this issue, a separation-based constraint formulation is developed that constrains buffet onset in an aerodynamic shape optimization. This separation metric is verified against a common buffet prediction method and validated against experimental wind-tunnel data. A series of optimizations based on the AIAA Aerodynamic Design Optimization Discussion Group’s wing–body–tail case are presented to show that buffet-onset constraints are required and to demonstrate the effectiveness of the proposed approach. Although both single-point and multipoint optimizations without separation constraints are vulnerable to buffeting, the optimizations using the proposed approach move the buffet boundary to make the designs feasible.