Optimization of Turbomachinery Airfoils with a Genetic/ Sequential-Quadratic-Programming Algorithm

Theobjectiveofthisaerodynamicshapedesigneffortistominimizetotalpressurelossacrossthetwo-dimensional linear-airfoil cascade row while satisfying a number of constraints. They included e xed axial chord, total torque, inlet and exit e ow angles, and blade cross-section area, while maintaining thickness distribution greater than a minimum specie ed value. The aerodynamic shape optimization can be performed by using any available e owe eld analysis code. For the analysis of the performance of intermediate cascade shapes, we used an unstructuredgrid-based compressible Navier ‐Stokes e owe eld analysis code with a k‐ turbulence model. A robust genetic optimization algorithm was used for optimization, and a constrained sequential quadratic programming was used for enforcement of certain constraints. The airfoil geometry was parameterized using conic section parameters and B-splines, thus keeping the number of geometric design variables to a minimum while achieving a high degree of geometric e exibility and robustness. Signie cant reductions of the total pressure loss were achieved using this constrained method for a supersonic exit e ow axial turbine cascade.