Aerodynamic Optimization Design of the Supersonic Aircraft Based on Discrete Adjoint Method

The study on the aerodynamic optimization design of the SSA(supersonic aircraft) is presented. And a gradient-based aerodynamic optimization system is build, which includes the FFD (free-form deform) parameterizatioN technique, the discrete adjoint technique based on RANS(Reynolds Averaged Navier-Stokes)equations, the mesh deformation technique based on IDW(Inverse distance weighting) and the gradient-based optimization algorithm based on the sequential quadratic programming. With the application of the system, the elaborate parameterization and thickness constraints considering structure and volume are realized on the SSA, leading to a aerodynamic optimization research aiming at the minimum of the aircraft drag. The results of optimization case shows that the aircraft drag is reduced by 5.7%, and the shock wave of the wing weakens, also, the pressure distribution in the mid and outer wing has a lower negative pressure peak of the leading edge, a weaker adverse pressure gradient and a more gentle pressure recovery.