Evaluation of CFD predictions using thermal field measurements on a simulated film cooled turbine blade leading edge

Computations and experiments were run to study adiabatic effectiveness and thermal field contours for a simulated turbine blade leading edge. The RKE and SST k-[omega] turbulence models were used for the computational simulations. Predictions of RKE model for laterally averaged adiabatic effectiveness matched the experimental values. The computational simulations showed different flowfield for the coolant exiting the stagnation line row of holes. Both the experiments and SST k-[omega] simulations predicted coolant separation at the stagnation plane. Also, the downstream spreading of the coolant exiting the stagnation row of exit holes was better predicted by the SST k-[omega] model. At the stagnation plane, experimental thermal field measurements showed greater diffusion of the coolant into the mainstream than predicted by both turbulence models. Reasons for increased diffusion were examined. Thermal field comparison downstream of the offstagnation row of exit holes showed that the computational simulations and the experiments had the same general shape for the offstagnation coolant jet. But the computational simulations predicted greater diffusion of coolant in the direction normal to the surface than seen in the experiments.