Effect of a Combined Hot-Streak and Swirl Profile on Cooled 1.5-Stage Turbine Aerodynamics: An Experimental and Computational Study

Abstract Recently developed lean-burn combustors offer reduced NOx emissions for gas turbines. The flow at exit of is dominated by hot streaks and residual swirl, which have been shown—individually—to impact turbine aerodynamic performance. Studies shown that swirl inlet to the high-pressure (HP) stage predominantly affects vane aerodynamics, while affect rotor aerodynamics. also these changes HP aerodynamics can downstream intermediate-pressure (IP) Yet, date, there no published studies presenting experimental test data with both simultaneously present inlet. This paper presents first computational investigation into effects combined on Experimental measurements were conducted in Oxford Turbine Research Facility (OTRF), a short-duration rotating transonic facility, nondimensional parameters relevant fluid mechanics heat transfer are matched engine conditions. under recently commissioned LEMCOTEC turbine, has designed represent modern aero-engine architectures robustness combustor-representative flows. comprises an unshrouded fully film-cooled vanes followed low-turning IP S-shaped duct. Two flows considered. uniform total pressure, temperature, angle. second features nonuniform temperature (hot streak) profile featuring strong radial weak circumferential variation superimposed swirling velocity profile. generated using new combustor simulator OTRF. Detailed area surveys inlet, exit, loading distributions measured vanes. Measurements unsteady Reynolds-averaged Navier–Stokes (URANS) predictions suggest nonuniformity was relatively well preserved upon being convected through turbine: predicted root-mean-square field approximately double Relatively poor comparisons between URANS experiment highlight challenge accurately predicting complex flow. In particular, small differences whirl angle resulted substantial thus pressure gradient.