Designs for future aero engines aim for increased efficiency with reduced exhaust gas and noise emissions. To achieve these goals, comprehensive physical understanding and highly innovative solutions are necessary. Even though computational capabilities are rising, the required confidence level is restrained. To understand and validate theoretical and numerical models, extensive experiments at realistic operating conditions are crucial. The modular compressor at the Transonic Compressor Darmstadt test facility at Technical University of Darmstadt enables investigations of prototype BLISK rotors in single or 1.5-stage setups, operating at high-speed conditions. Extensive steady and time-resolving instrumentation is used to determine the compressor aerodynamics and performance as well as aeroelastics. To foster improvements in numerical modelling and predictability based on high quality experimental data, the TUDa-GLR-OpenStage test case is introduced. It comprises a single stage setup, including the BLISK rotor, a 3D-optimized stator as well as the annulus contour. The data set is supplemented with comprehensive measurement data at stage inlet and outlet as well as running tip clearances. This paper describes the open test case, related geometries, measurement procedures and corresponding experimental results, including steady state performance and unsteady aerodynamics. Ultimately, it is aiming to provide a standard case for future development of numerical models and comparable validation.

The aerothermal interaction of the combustor exit flow on the first vane row has been examined at the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt (Darmstadt, Germany). A baseline configuration of axial inflow and a variation of swirling combustor inflow have been studied. The nozzle guide vane (NGV) featured endwall cooling, airfoil film cooling and a trailing edge slot ejection as well as NGV-rotor wheel space purge flow. CO₂ is injected for coolant flow tracing. The results are compared to five hole probe (5HP) measurements. The experiments for the baseline configuration are accompanied by numerical simulations using a passive scalar tracking method to validate the results and study the propagation of the coolant flow. The endwall coolant injection is detected to influence the pressure losses in the NGV. It has an impact on the Trailing Edge (TE) coolant ejection as well. For swirling combustor inflow, increased NGV pressure losses and increased mixing of Rear Inner Discharge Nozzle (RIDN) coolant and main flow is observed. An influence of the clocking position of the swirler to the vane is detected. Additional losses within the NGV row can be assigned to the swirler by means of flow tracing.

In order to fully understand the physical behavior of lean burn combustors and its influence on high pressure turbine stages in modern jet engines, the use of Computational Fluid Dynamics (CFD) promises to be a valuable addition to experimental techniques. The numerical investigations of this paper are based on the Large Scale Turbine Rig (LSTR) at Technische Universität Darmstadt, Germany which has been set up to explore the aerothermal combustor turbine interaction. The underlying numerical grids of the simulations take account of the complex cooling design to the fullest extent, considering coolant cavities, cooling holes and vane trailing edge slots within the meshing process. In addition to the k-ω-SST turbulence model, Scale-Adaptive Simulation (SAS) is applied for a computational domain comprising swirl generator and nozzle guide vanes in order to overcome the shortcomings of eddy viscosity turbulence models with regard to streamline curvature. The numerical results are compared with Five Hole Probe measurements at different streamwise locations showing good agreement and allowing for a more detailed examination of the complex flow physics caused by the interaction of turbine flow with lean-burn combustion and advanced film-cooling concepts. Moreover, numerically predicted Nu-contours on the hub end wall of the nozzle guide vane are validated by means of Infrared Thermography measurements.