Experimental and Computational Investigation of the Time-Averaged and Time-Resolved Pressure Loading on a Vaneless Counter-Rotating Turbine

The experimental program reported here was executed using full-scale vaneless counter-rotating engine hardware operating at nondimensionally scaled aerodynamic design point conditions. Measurements were obtained for three different pressure ratio values: design point, low pressure ratio, and high pressure ratio. For brevity, only the design point data will be presented in this paper. Time-averaged and time-resolved surface pressures on the high pressure turbine (HPT) vane, HPT blade, and low pressure turbine (LPT) blades are presented. Additionally, three-dimensional (3D) Navier-Stokes computational fluid dynamics (CFD) predictions are presented for comparison with experimental data. The results presented show that the predictions qualitatively capture the flowfield physics, but require some additional calibration to fully match experimental data quantitatively.