| Large–Eddy Simulations (LES) of trailing-edge cutback film cooling are performed for various blowing ratios M. The geometry and the Reynolds number are chosen to match the setup of an existing experiment. From the LES data the film cooling effectiveness Eta_aw is determined as a function of the streamwise coordinate x/H and M. Contours of Eta_aw in the x/H - M plane form a map that serves to identify local performance extrema and critical operating points. These topological features in the Eta_aw map are shown to be strongly correlated with changes in the kind and/or strength of large coherent structures (LCS). However, it is also demonstrated that the sole identification of coherent structures is not sufficient to properly assess their impact on heat transfer. Therefore, also statistical properties of the flow and temperature fields are related to the LCS. |
