Penetration characteristics of film-cooling jets at high blowing ratio

Reynolds-Averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) methods are used to analyze film cooling at high blowing ratios. Numerical predictions are compared with experimental data to identify shortcomings of these models in predicting film cooling flows. Symmetry boundary conditions are applied along the jet centerline and along the line of symmetry between two adjacent jets. The CFD code used in this study is Glenn-HT, an in-house research code developed at the NASA. CFD is found to be able to capture the vertical extent of the mixing accurately and shows that the mixing region extends two hole diameters from the wall similar to experimental results. The CFD predicts near-wall temperatures in the range of 0.9 to 0.4, while the lateral extent of the film shows the film extending to one hole diameter from the wall.