Effects of Anticlockwise Swirling Inflow on the Aerothermal Performance of the Turbine Vane Endwall with Film Cooling Layouts

Abstract

The large swirling flow downstream the lean burn premix combustor significantly impacts on the aerothermal performance of the first stage turbine vane endwall. The effects of the anticlockwise swirling inflow on the aerothermal performance of the turbine vane endwall with film cooling layouts was numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes (RANS) and SST turbulence model. The heat transfer characteristics and film cooling effectiveness of the turbine vane endwall with three rows film holes along the axial direction at three kinds of inlet swirl number 0.6, 0.8 and 1.0 was analyzed and compared. The obtained results show that the anticlockwise swirling inflow leads to the horseshoe vortex of the vane endwall migrate to the downstream and generate the recirculation vortex of the mainstream by comparison to the uniform inflow condition. The anticlockwise swirling inflow changes the Nusselt number distribution of the vane endwall and results in the high heat transfer coefficients regions. The high heat transfer regions at the vane endwall increases with the swirling inflow strength increases. The anticlockwise swirling inflow enhances the Nu downstream the first row film holes at the x/Cax=0.31 and suppresses the coverage of the coolant jet from the film holes migration to the suction side. Comparison to the uniform flow condition, the averaged film cooling effectiveness of the first row film holes increases up to 27% and the third film holes decreases about 9%.