Electrodynamic enhancement of film cooling of turbine blades

Three concepts are numerically investigated to promote lateral mixing of the cold jets and to ensure their better attachment to the surface. First, we introduce electrodynamically enhanced interaction of cool air jets with hot crossflow for improved cooling of hot surfaces. We identify mechanisms to "push" or "pull" the essentially stagnant fluid just downstream of the hole by enforcing an active pressure pulsation in streamwise and crosswise directions. Such method utilizes electrodynamic force that induces attachment of cold jet to the work surface by actively altering the body force in the vicinity using a plasma actuator for different cooling hole geometries. Second, we employ a negative pressure region just downstream of the cooling hole. This may be generated by utilizing a suction vent or other mechanisms. Third, we propose three geometric modifications of the cooling hole exit for enhancing lateral tripping of the cold jet. Detailed computation of a single row of 35 degree round holes on a flat plate has been obtained for a select blowing ratio of 1.0 with a density ratio of 2.0. Results are compared with the published experimental results and other numerical predictions for the latest film cooling technology to identify effectiveness improvement. We have shown that a combination of plasma and geometric change can significantly improve the film cooling performance.