Large-Eddy Simulation of Shaped Hole Film Cooling with the Influence of Cross Flow

Abstract

Abstract In the highly-loaded turbine blade passage, cross flow is driven by the lateral gradient. It strongly influences the cooling performances in the endwall region. In this research, the effect of cross flow on the shaped film cooling hole is studied by Large Eddy Simulation (LES); modal analysis is conducted with an incremental POD (iPOD) approach, which makes the analysis of the large data sets from LES feasible. It is shown that the symmetry of the counter rotating vortex pair (CRVP) is destroyed. The large-scale vortex induced by end-wall cross flow plays an important role in both shape and convection of hairpin vortices and horseshoe vortices, which influences the coolant distribution. This study suggests that the effects of cross flow should be considered for the design of end-wall film cooling. It also indicates the high efficiency of the iPOD approach, which can be used to analyze large amounts of high-dimensional data.