Centrifugal Compressor Retrofit: Geometry Rebuild and 3-D Blade Shape Optimization

This article summarizes the development of an aerodynamic retrofit for a centrifugal compressor stage. In the first part, a method to replicate the open design case'Radiver' (RWTH Aachen University), using an in-house tool (NarTIG) is presented. The geometry is then used as a starting point for a 3D aerodynamic full stage blade shape optimization. The results of the optimization are shown in the second part of the paper. The results of the fully 3D-optimized profiles of the impeller blades and diffuser vanes show a significant reduction of spanwise leading edge loading, leading to an increase of 2-percentage points in total-static polytropic efficiency at optimal conditions. An increase of 20-percentage point with respect to high flow conditions is also reached.