Effect of Inlet Temperature Non-Uniformity on High-Pressure Turbine Performance

Abstract

The temperature of the flow entering a high-pressure turbine stage is inherently non-uniform, as it is produced by several discrete, azimuthally-distributed combustors. In general, however, industrial simulations assume inlet temperature uniformity to simplify the preparation process and reduce computation time In the VI configuration, the hot streaks produced higher time-averaged heat load on the vanes and lower heat load on the blades. As the hot streaks in the VI case passed over the stator vanes, they also spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. The hot streaks in the MP case were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration. The non-uniformity of the time-averaged enthalpy on the blade surfaces was lower in the VI configuration. The flow exiting the rotor section was much less non-uniform in the VI case, but differences in calculated efficiency were not significant. i for Claudine and Henri ii

Numerical Study of the Axial Gap and Hot Streak Effects on Thermal and Flow Characteristics in Two-Stage High Pressure Gas Turbine

“…Feng et al found that the second-stage stator exhibits a high efficiency and low thermal load when its clocking position and HS were aligned [6]. Smith found that the time-averaged heat load when the HS is aligned with the stator had a large effect on the stator and a small effect on the rotor compared with the case when the HS is aligned with the stator passage [7]. However, these studies did not consider the effect of axial gap (AG) on the thermal and flow characteristics of the blade surface.…”

Heat transfer characteristics of a high-pressure turbine under combined distorted hot-streak and residual swirl: an unsteady computational study

“…A hot-streak positioned on front of the vane LE generates more heat transfer rate than a hot-streak positioned on front of the passage. Smith et al [12] studied numerically the effects of hot-streak clocking position on a HPT stage. They reported that the aligned hot-streak with the vane LE produces higher thermal load on the vanes and lower thermal load on the rotor blades.…”

“…The isolated effects of the residual swirl only, or the hot-streak only on the aerothermal performance of high-pressure turbines (HPT), are well studied in the literature, on either non-rotating vanes or rotating turbine stages [6][7][8][9][10][11][12][13][14][15][16][17] . Key experimental and computational fluid dynamics (CFD) findings from such isolated effects studies are summarised below.…”