Multipoint and Multi-objective Optimization of Airfoil Considering Boundary Layer Ingestion

Abstract

Blended-wing-body (BWB) aircraft concept coupled with distributed propulsion is proposed as a potential configuration to meet the N?+?3 goals. In this configuration, the boundary layer ingestion (BLI) effect resulting from the distributed propulsion enhances the aircraft?s aerodynamic performance significantly. The inlet&outlet boundary interacts with the upper airflow strongly, so that the pressure distribution differs from a clean airfoil. However, previous optimization design works mainly aimed at clean airfoil design at cruise conditions. Thus, in this paper, a two-dimensional section of this configuration considering the inlet&outlet boundary conditions of the propulsion system is designed through a multipoint optimization at cruise and climb conditions. We achieve a high lift to drag ratio 2D shape at cruise conditions while improving its climb performance. In addition, we use a weighted-integral method to improve the robustness of the optimal solution and enlarge the drag-divergence Mach number of the solution significantly. Our results may provide qualitative guidance on the future three-dimensional optimization design of the advanced aircraft aerodynamic shape.