Turbine vane endwall aerothermal and film cooling performance considering realistic swirling inflow conditions

Abstract

The turbine vane inlet downstream of the lean premixed combustor presents nonuniform distributions of velocity and temperature. For obtaining swirling inflow profiles close to reality, the simulated non-reacting combustor is designed firstly. Applying these profiles as inflow boundary conditions, the effects of realistic swirling inflow on the turbine vane endwall aerothermal characteristics and film cooling performance are numerically investigated through solving the three-dimensional Reynolds-Averaged Navier-Stokes equations coupled with the shear stress transfer ([Formula: see text]) turbulence model. Two swirling orientations (anticlockwise and clockwise) and five swirling core pitch-wise positions (aligned with vane 1 to vane 2) are considered in the current work. The results indicate that the residual vortices in the vane passage are strengthened and move with the swirling core along the pitch-wise direction. The migration of the horseshoe vortex is controlled by this movement. The shrinkage or expansion of the separation line of the horseshoe vortex can be observed under the anticlockwise and clockwise swirling inflow conditions respectively. The anticlockwise swirling inflow results in a larger aerodynamic loss by a 10%–35% increase of the laterally [Formula: see text]. The high Nu region near the pressure side surface enlarges and the area-averaged Nu at [Formula: see text] increases from 2337.9 to 2878.3. For the cases with clockwise swirling inflow, the area of the hot ring is enlarged and the Nu downstream of the row 3 film holes is decreased. As for the film cooling performance, the endwall coverage area shrinks and the phantom cooling area enlarges when the anticlockwise swirling core is aligned with vane 2. The endwall loses the protection from the row 3 film holes and the cooling failure ([Formula: see text]) occurs at [Formula: see text] when the swirling core is aligned with the vane passage. This is an extremely bad phenomenon that should be avoided. Among all cases, the highest endwall area-averaged [Formula: see text] (0.122) is obtained when the clockwise swirling core is aligned with vane 1. The largest endwall coverage area is achieved when the clockwise swirling core is aligned with vane 2.