Computational Study of Parameters Affecting Turbulent Flat Plate Film Cooling

Abstract

Blade film cooling is one of the best methods to improve efficiency of gas turbines. In this work, two different methods of film cooling, namely, slot injection and discrete hole injection have been numerically studied on a flat plate. Incompressible, stationary, viscous, turbulent flow has been simulated using the FLUENT CFD code with the standard k-ε model. The study of injection angle and velocity ratio show that the optimum film cooling in both methods, occurs at the jet angle of 30° but with the velocity ratio of 1.5 for slot case and 0.5 for discrete hole case. The study of jet aspect ratio in discrete hole method, shows that stretching the hole in spanwise direction increases the film cooling effectiveness. Because it not only cool a larger region in both spanwise and streamwise directions, but also can sustain the cooled flow closer to the blade's wall. The study of jet spacing shows that increasing the jet spacing decreases the effectiveness but not as much as jet aspect ration does.

Effects of Swirl Velocities From Fan Assemblies Mounted on Lifting Surfaces

“…In addition, Hu and Ji [15] investigated, numerically, the eftect of blowing angle, illustrating that increased film-cooling effectiveness is achieved at higher blowing angles. On the other hand, regarding intemal cooling applications, several attempts have been made to improve the heat transfer coefficient by increasing turbulence levels on the flow near the cross section of the jet [16]. The installation of a triangular vortex generator just downstream of the cool-LEFTSIDI RIGHT SIDE Fig.…”