A Combined Experimental and Numerical Investigation of the Flow and Heat Transfer Inside a Turbine Vane Cooled by Jet Impingement

Abstract

The present study aims at characterizing the flow field and heat transfer for a schematic but realistic vane cooling scheme. Experimentally, both velocity and heat transfer measurements are conducted to provide a detailed database of the investigated configuration. From a numerical point of view, the configuration is investigated using isotropic and anisotropic Reynolds-averaged Navier–Stokes (RANS) turbulence models. A hybrid RANS/large eddy simulation (LES) technique is also considered to evaluate potential unsteady effects. Both experimental and numerical results show a very complex three-dimensional (3D) flow. Air is not evenly distributed between different injections, mainly because of a large recirculation flow. Due to the strong flow deviation at the hole inlet, the velocity distribution and the turbulence characteristics at the hole exit are far from fully developed profiles. The comparison between particle image velocimetry (PIV) measurements and numerical results shows a reasonable agreement. However, coming to heat transfer, all RANS models exhibit a major overestimation compared to IR thermography measurements. The Billard–Laurence model does not bring any improvement compared to a classical k–ω shear stress transport (SST) model. The hybrid RANS/LES simulation provides the best heat transfer estimation, exhibiting potential unsteady effects ignored by RANS models. Those conclusions are different from the ones usually obtained for a single fully developed impinging jet.