Investigation of film cooled turbine with conjugate heat transfer using source term model

The NASA C3X cascade with 10 radial internal cooling holes and five rows of film cooling holes in the leading edge was studied in this paper. Firstly, the conjugate heat transfer (CHT) method was employed in the non-film-cooled blade to simulate the heat transfer between the main flow and the internal coolant with the blade. The turbulence models included B-L model (zero-equation model), S-A model (one-equation model), SST model (two-equation model) and S-A model with AGS transition model. Experiment results were compared with the simulation results, and S-A model was selected for next step considering its reasonable prediction of eddy viscosity. Secondly, the source term model was used to simulate the film cooling effect by adding mass flux, momentum flux, energy flux and turbulence energy flux on the cells where the film holes were located. The method was able to save a lot of time without discretization of every single hole, which is convenient for modern film-cooled turbine design. The feasibility of the source term model was discussed through a comparison between the simulation and experiment results. The effect of the film cooling on the internally cooled vane was also discussed, and detailed mechanism of the heat transfer among the internal and external coolant, hot air, and the blade was analyzed.