A Database of Optimal Airfoils for Axial Compressor Throughflow Design

Abstract

This text describes methods to organize a large set of optimized airfoils in a relational database and its application in throughflow design. Optimized airfoils are structured in five dimensions: inlet Mach number, blade stagger angle, pitch-chord ratio, maximum thickness-chord ratio and a parameter for aerodynamic loading. In this space, a high number of airfoil geometries is generated by means of numerical optimization. Each airfoil geometry is tailored to its specific requirements and optimized for a wide working range as well as low losses. During the optimization of each airfoil, performance in design and off-design conditions is evaluated with the blade-to-blade flow solver MISES. Together with airfoil geometry, the database stores automatically calibrated correlations which describe cascade performance in throughflow calculation. Based on these methods, two subsonic stages of a 4.5-stage transonic research compressor are redesigned. Performance of baseline and updated geometries is evaluated with 3D CFD. The overall approach offers accurate throughflow design incorporating optimized airfoil shapes and a fast transition from throughflow to 3D CFD design.