Flow control techniques enabling increased pressure ratios in aero engine core compressors for ultra-high propulsive efficiency engine architectures
The ultra-high propulsive efficiency demonstrator engine developed by Safran Aircraft Engines and GE Germany (GEDE) within Clean Sky 2 promises a considerable reduction of pollutant and noise emissions as well as aero engine fuel burn. While the geared architecture allows a further increase in bypass ratio and thus propulsive efficiency, a core engine with increased pressure ratio maximizes the turbofan´s thermal efficiency and performance. However, the increased pressure ratio within the HPC demands a reduction of the flow cross section, which results in larger relative clearances and endwall boundary flows that penalize the compressor efficiency and operability.
The objectives of the proposed project are, first, to develop an innovative HPC rear stage concept that addresses the challenging aerodynamics associated with increased rotor clearances by combining the casing treatment technology with complimentary flow control techniques to strengthen the flow across the entire span, second, to provide a high-speed, large-scale multi-stage compressor test facility and execute an engine-representative rig test to validate the rear stage concepts collaboratively developed by GEDE and the Technische Universität München (TUM), third, to apply advanced data acquisition techniques that provide a detailed compressor performance and operability assessment as well as a thorough understanding of the unsteady flow physics and aerodynamic loss mechanisms.
TUM´s years of experience in aerodynamic blade design and the development of flow treatment technologies in conjunction with its high-speed compressor test facility that is particularly suited for the validation of compressor rear stage concepts as well as the institute´s proven capability to successfully execute rig tests on an industrial standard will greatly benefit GEDE´s research efforts and ensure a technology maturation to TRL5, thus, allowing for a subsequent technology validation in a ground test demonstrator.