Numerical Study on Flat Plate and Leading Edge Film Cooling

Abstract

This study describes a 3-D computation for film cooling effectiveness investigation using Fluent commercial code, version 6.2. Two configurations are examined: (1) Flat plate, and (2) Semi-cylindrical leading edge with a flat after-body. Three different RANS turbulence models and DES based on Spalart-Allmaras model are utilized to see the difference in accuracy between DES and RANS approaches. Similar to the previous RANS simulation, lateral spreading of film cooling is under-estimated in the RANS simulation, while in the DES, lateral spreading of film cooling is enhanced and shows adequate agreement with the previous experiments. The effects of velocity magnitude and orientation of plenum flow on film cooling effectiveness are also studied in the flat plate configuration. The plenum flow is eventually found to have a strong impact on the flow structure in the cooling pipe, and the distorted velocity profile in the pipe consequently lowers film cooling effectiveness, in particularly at high blowing ratio.