Design of a Highly-Loaded Four-Stage Low-Speed Research Compressor

Abstract

The present paper describes the design of a new set of blades for the four-stage axial-flow low-speed research compressor (LSRC) at the TU Dresden. The compressor contains nine blade rows: IGV, four rotors and four cantilevered stators designed as repeating stages. The compressor was originally designed and built in the German AG Turbo project. In recent years fourteen builds of the compressor were built and tested [1]. The new design of the NGV (Build A15) has increased pressure ratio and loading compared to the previous builds. The design was performed using a method giving three-dimensionally optimised blades achieving better efficiency than the previous builds with sufficient operating range despite increased loading. The numerical analysis was carried out using a Rolls-Royce 3D-Navier-Stokes solver at design and off-design inlet conditions. The experimental investigations were carried out by the Technical University of Dresden. Overall performance was measured for different speeds and different back-pressures up to compressor stall. Flow field details were measured at a design and a close-to-stall condition using static pressure probes on the blade suction and pressure surface and secondary flow measurements using 5-hole probes.