Curvature driven two-dimensional multi-objective optimization of compressor blade sections

This paper introduces a new curvature based design parameterization of two-dimensional high pressure compressor blade sections to be used in a multi-criteria aerodynamic design optimization process. The suction side of the airfoil section is represented by its curvature distribution which is described by a B-spline curve. The coordinates are then derived by numerical integration. The camber line as well as pressure side are obtained by adding a thickness distribution perpendicularly to the camber line. The thickness distribution itself is modeled as a B-spline curve as well and varied during optimization. In order to achieve smoothness between leading edge, trailing edge and pressure side, respectively, specific conditions for the control points of the thickness distribution are derived. The resulting compressor blade section is optimized w.r.t. pressure loss and working range using process integration and a genetic algorithm. The results show major improvements over a manually “optimized” datum design regarding both criteria.