Aerothermal Flow Characterization

The Aero Rig Enclosure (ARE) is a test facility at GE Research that enables independent control of Mach number and Reynolds number for an installed test article. A secondary flow supply system, which can inject mixtures from 100% air to 100% CO2, is also available. While the flexibility of the ARE allows for any number of arrangements, the most frequent application has been for turbomachinery cascades through the use of GE Research's high-speed moving bar (HSMB) rig.

The HSMB rig consists of a multi-passage linear cascade of airfoils behind a rotating wheel with attached bars that simulate an upstream airfoil’s wake. The HSMB rig, within the ARE, can achieve transonic conditions (~Mach 1.2) at Reynolds numbers ranging from LPT cruise (<300K) to HPT takeoff (1M+). The rotating bars produce very high linear speeds at the cascade inlet, allowing for engine-relevant through-flow coefficients.

Using traditional pneumatic instrumentation (3D pressure probe traverses) and pressure sensitive paints, aerodynamic loss and film cooling effectiveness can be quantified. Imaging capabilities in the ARE and HSMB, including Schlieren photography and PIV measurements, further enable visualization of flow details for both steady and unsteady conditions, providing invaluable data for highlighting individual sources of loss and for calibration/benchmarking of CFD.

Several LPT and HPT airfoil cascades have been examined in the HSMB and ARE facilities to understand incoming wake effects on turbine airfoil profile loss. Steady and unsteady loss trends for HPT and LPT airfoil loading style, and for HPT blade reaction, have been developed with HSMB data. Testing is also underway to examine the impact of different film cooling designs, under both steady and unsteady inlet conditions, on the aero-thermal performance of an HPT turbine blade. Insights provided by these tests have enabled the Aviation and Power businesses to adjust their aerodynamic and cooling designs to reduce fuel burn.