Conjugate Flow and Heat Transfer Mechanism between the Rib Cooling and Film Cooling

Abstract

Rib cooling and film cooling are the effective cooling schemes to meet the increasing demands of rising turbine inlet temperatures in modern gas turbine engines. Most studies have been carried out to find the flow and heat transfer characteristic of rib cooling or film cooling individually. While the conjugate heat transfer between these two cooling methods is rarely studied in the literature. In order to evaluate the interplay between the rib cooling and film cooling, the conjugate flow and heat transfer mechanism in two perpendicular flat plate channels connected by a conductive solid wall with a compound film hole through it is studied numerically. Ribs are arranged in the internal cooling channel and the heat conduction in the connecting wall and ribs are considered. The blowing ratios vary from 0.75 to 1.5. SST κ-ω and large-eddy simulation (LES) turbulence model are checked to find the applicability of the turbulence models in this simulation by comparing the numerically predicted results with the experimental results from literature. The results indicate that LES is better at capturing the fine structure of the flow field and has higher accuracy. The arrangement of film hole strengthens the heat transfer capacity of the internal cooling channel. However, the arrangement of ribs reduces the overall cooling efficiency of the mainstream cooling channel.