Parametric Optimization of a High-Lift Turbine Vane

Numerical optimization techniques are increasingly used in the aerodynamic design of turbomachine blades. In the present paper, an existing three-dimensional high-lift turbine cascade was redesigned by means of CFD analyses and optimization techniques, based on the blade geometrical parameterization. A new parametric design tool was developed for this purpose. Blade geometry was handled in a fully three dimensional way, using Be´zier curves and surfaces for both camber-surface and thickness distribution. In the optimization procedure different techniques were adopted: a Genetic Algorithm (GA) strategy made it possible to considerably reduce two-dimensional profile losses, while the optimal stacking line was found based on a successive Design of Experiments (DOE) analysis. As a result, a new high-lift blade with higher performance was obtained; in addition, the effect of hub/tip leaning was presented and discussed.