AN ASSESSMENT OF TURBULENCE MODELS FOR PREDICTING CONJUGATE HEAT TRANSFER FOR A TUBINE VANE WITH INTERNAL COOLING CHANNELS

In this study, five models, including the standard k-epsilon (SKE), realizable k-epsilon (RKE), SST k-omega, transition k-kl-omega, and the v(2)f model, are considered to simulate air flow and heat transfer of a turbine guide vane. The object in this paper is the well-studied NASA C3X turbine vane, for which experimental data are available. Ten internal cylindrical cooling channels are used to cool the blade. Three-dimensional temperature distributions of the turbine vane were obtained by a fluid-solid conjugated model including the external aerodynamic flow, internal convection and heat conduction region within the metal vane. In order to validate the computational results, the temperature distributions, static pressure distributions, and heat transfer coefficient distributions along the vane external mid-span surface are compared with experimental data. The 4-5-2-1 arrangement of the C3X cascade is selected, and the fluid is assumed to be an ideal gas. The results reveal that the SST k-omega turbulence model performs quite well in predicting the conjugate heat transfer. Detailed heat transfer distributions in the main passage are also shown. The representative transitional behavior of the C3X vane on both pressure and suction surfaces is further analyzed. It suggests that the transition behavior plays a significant role in predictions of the boundary-layer behavior, wall temperature distribution, and heat transfer performance.