Low Engine Order Stage Tests at DLR (Time-Averaged Results)

As part of the Brite/EuRam project "Aeroelastic Design of Turbine Blades II" (ADTurBII) Low Engine Order (LEO) experiments in a high pressure turbine stage with stator coolant flow and throat area ariation have been carried out in the windtunnel for rotating cascades (RGG) at DLR in Gottingen. Total pressures in the rotor exit flow field were measured by pitot probe at up to 8 radial locations between 10% and 90% channel height. 2D-velocity vectors and turbulence intensities in the tator-rotor gap and in the rotor exit field were measured by a Laser-2-Focus (L2F) anemometer at 20%, 50% and 90% height. Investigations were performed for a low and high pressure ratio, covering at least one period of low engine order (up to 9 stator passages). Only time averaged results are presented and evaluated. A Fourier analysis reveals the harmonic contents of the low engine order flow field. Local homogeneous (mixed out) flow field quantities were calculated for every low engine order stator pitch.