Film cooling in gas turbine engine designs has shown great benefit over the years. Film cooling flows perturb the boundary layer flow, however, as they emerge from discrete holes. The impact on aerodynamics is experimentally evaluated for both streamwise and lateral film cooling injection. Injection is with a hole length-to-diameter ratio of 2.3 and a 35° angle of inclination. Data for two coolant-to-freestream momentum flux ratios, 0.25 and 1.0, with a high freestream turbulence intensity of 11.3% are given. Comparisons are made to similar cases without coolant injection. Evaluation is in terms of momentum thickness, shape factor, and skin friction coefficient distributions. Turbulence data are also provided. The injection geometry and coolant-to-freestream momentum flux ratio are shown to greatly influence aerodynamic penalties. Lateral injection imposes more losses, but lower skin friction values, than does streamwise injection. In some instances, the emerging coolant is capable of energizing the boundary layer, reducing losses relative to those present without coolant injection.
|Original language||English (US)|
|Number of pages||8|
|Journal||American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD|
|State||Published - Dec 1 1998|
|Event||Proceedings of the 1998 ASME International Mechanical Engineering Congress and Exposition - Anaheim, CA, USA|
Duration: Nov 15 1998 → Nov 20 1998