Analysis of Internal Cooling Geometry Variations in Gas Turbine Blades

The present investigation analyzes the effects of major geometrical modifications to the interior of a convection cooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on the heat transfer. An experimental approach is performed with flow visualization via paint injection into water, Also numerical calculations are carried out in two sets, on the one hand water calculations accompanying the experiments and on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculations are still ongoing delivering preliminary results. Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leading edge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modified geometries the pressure ratio is held constant compared to the base. Among several investigated configurations one could be identified that leads to a heat transfer enhancement in one leading edge channel 7 % larger compared to the base.