Session: Student Poster Competition

Submission Number: 185961

Impact of Inlet Swirl on an Aft Centrifugal Compressor Stage Design for an Axial-Centrifugal Compressor in Aero Engines 

The combination of axial and centrifugal compressors is a widely adopted concept in small turbofan and turboshaft engines for helicopter propulsion. However, in medium and large turbofans, purely axial compressors have remained the standard. With increasing pressure ratio requirements and the development towards small core dimensions, secondary flow losses in the small stages towards the back end of axial compressor become critical. Thus, integrating a centrifugal stage at the end of an axial compressor by replacing these rear axial stages becomes a viable alternative. The interaction of the axial stages with the aft centrifugal stage is a particular challenge and must be taken into account during the design process.
This poster presents the parametric study of inlet swirl in a centrifugal stage that consist of an impeller, wedge diffuser, 90° bend and an outlet guide vane. The study is based on an initial aerodynamic design of a centrifugal stage tailored to meet specific performance targets, including a defined overall pressure ratio and exit flow requirements. Following the baseline design process, the investigation focuses on the impact of varying inlet swirl levels originating from the upstream rear axial stator on the aerodynamic performance of the isolated centrifugal stage as well as on the overall compression system. The centrifugal stage was redesigned for increased and reduced levels of inlet swirl, while keeping the stage pressure ratio constant. This approach enables a direct comparison of the stage isentropic efficiency and loss development through the components of the centrifugal stage.

Presenting Author: Sidharath Madaan Chair of Turbomachinery and Flight Propulsion,Technical University Dresden

Presenting Author Biography: Sidharath Madaan is a Research Associate at the Chair of Turbomachinery and Flight Propulsion at Technical University Dresden, focusing on the development of robust axial compressor stages for axial-radial configurations. Following a Bachelor's in Mechanical Engineering, he earned a Master’s from FAU Erlangen-Nürnberg, specializing in thermal and fluid sciences.

Authors:

Sidharath Madaan Chair of Turbomachinery and Flight Propulsion,Technical University Dresden
Martin Lange Chair of Turbomachinery and Flight Propulsion, Technical University Dresden
Mirco Rostamian Rolls-Royce Deutschland Ltd & Co KG
Ronald Mailach Chair of Turbomachinery and Flight Propulsion, Technical University Dresden