Investigation of Interacting Mechanism between Film Cooling and Internal Cooling Structures of Turbine Blade

This paper presents three-dimensional numerical simulations with the established realizable k-epsilon model to clarify the underlying and interacting mechanisms between the film cooling and the internal cooling. On the one hand, the effects of three different internal cooling channels, i.e., smooth channel, continuous ribbed channel, and truncated ribbed channel, on the film cooling effectiveness and the discharge coefficients are investigated. On the other hand, the influences of three different film cooling holes, i.e., cylindrical hole, two elliptical holes and two circular-to-elliptical holes, on the heat transfer performances and pressure loss of the internal cooling channel are revealed. Especially, the suction effects of the film cooling holes are analyzed through setting up baselines with only internal cooling channels. Results show that the placement of ribs in the internal channel has different influences on the film cooling effectiveness with respect to different hole shapes depending on the blowing ratio. The discharge coefficient of the film hole can be improved by introducing ribs to the internal channel. Suction of film hole is helpful for enhancing the heat transfer performance and reducing the pressure loss of the internal channel. Besides, ribs instead of the suction effect of film hole play a major role to enhance the heat transfer performance in the internal cooling channel.