Adjoint based aerodynamic shape optimization of a semi-submerged inlet duct and upstream inlet surface

Aerodynamic performance of a semi-submerged inlet exposed to a significant amount of boundary layer ingestion is optimized using the open-source flow and adjoint solver SU2. Pressure recovery is taken as the objective function. Mass flow rate and total pressure distortion at the aerodynamic interface plane are also monitored. Optimization is performed in two parts. First, the inlet duct is optimized while keeping the vertical offset and the total duct length fixed, and a limited improvement in performance is observed. Next, the wall surface upstream of the inlet, where the ingested boundary layer develops, is included in the optimization study. It is shown that the shape optimization now provides a boundary layer diverting inlet and a significant improvement is achieved in both pressure recovery and flow distortion.