Turbine Endwall Contouring for the Reduction of Endwall Heat Transfer Using the Ice Formation Method Along With Computational Fluid Dynamics

Turbine endwall contouring has become very popular for optimizing gas turbines. Increasingly often, three-dimensional contours are applied between turbine airfoils to reduce aerodynamic losses or heat transfer rates. These reductions directly result from the shaping of such contours which modifies the flow and thermal field in their vicinity. Here, we report on the development of novel endwall contours for a generic low pressure vane profile to reduce endwall heat transfer. Using the flat endwall as baseline, different endwall contours were created using the Ice Formation Method. This natural approach imposes only minimum restrictions on the design space and is therefore considered advantageous to other optimization procedures. The created contours were subsequently analyzed by Computational Fluid Dynamics simulations. Results showed that all created contours reduced endwall heat transfer compared to the baseline, the highest reduction being 7% in terms of the averaged endwall Stanton number. For this endwall contour, we performed detailed analyses of the numerically predicted flow and temperature fields to indicate how the shaping of this contour affects the flow and temperature fields and hence causes the observed heat transfer reduction.