Résumé
The film cooling technique is often used to protect the hot components in gas turbines engines by introducing cold air through small holes drilled in the wall. The hot products are mixed with the injected gas and the temperature in the vicinity of the wall is reduced. Classical wall functions developed for impermeable walls and used in Reynolds-Averaged Navier-Stokes methods cannot predict momentum/ heat transfer on perforated plates because the flow is drastically modified by effusion. In order to obtain a better understanding of the flow structure and predominant effects, accurate simulations of a turbulent flow around an effusion plate are reported. Large-Eddy Simulations of the flow created by an infinite multi-perforated plate are presented. The plate is perforated with short staggered holes inclined at an angle of 30 deg to the main flow, with a length-to-diameter ratio of 3.46. Injection holes are spaced 6.74 diameters apart in the spanwise direction and 11.68 diameters apart in the streamwise direction. Results for mean velocity and velocity fluctuations are compared with measurements made on the LARA large-scale isothermal experiment [1].