Numerical and Experimental Investigation of Tangential Endwall Contoured Blades in a 2-Stage Turbine

Abstract

This paper deals with the results of numerical and experimental investigations of tangential endwall contoured (TEWC) blades. The contouring is restricted to the blade passage and is implemented on the root and the shrouds for all blade rows. The investigated results of the new blade design have been compared to a reference blade design, which differs only in terms of the contouring. For this reason, the differences of the flow conditions can solely be attributed to the endwall contouring. All investigations have been carried out at different blade loadings in order to determine the potential improvement of the blading with respect to the efficiency. The analysis has emphasized an efficiency improvement for the design point and an efficiency decrease for high blade loading. The under- and overturning are considered by means of the angle distributions behind the stages and serve as an indicator for the losses caused by the passage vortex. An attenuation of the passage vortex in the casing area resulting from the load relief in the casing-sided area can be observed. The contouring in the hub-area however leads to a higher development of the horseshoe vortex at high blade loading.

Influence of Adjusting Control Accuracy on Pressure Probe Measurements in Turbo Machines

“…Further details according to the airfoil and sealing setup as well as for the uncertainty analysis can be found in Refs. [5,6].…”