External heat transfer on nozzle guide vanes under highly swirled combustor outlet flow

Nozzle Guide Vanes aero-thermal performance is commonly assessed in the industry using tangentially-averaged quantities, imposed at the combustor-turbine interface as inlet conditions for RANS models. However, recent studies have shown that scale-resolving approaches can reproduce the impact of unsteady fluctuations on turbulent mixing. An experimental test case with a combustor simulator and a nozzle cascade is investigated, comparing two numerical modelling strategies: i) Scale-adaptive simulation (SAS) including both combustor and turbine; ii) RANS simulation of the nozzles with SAS-derived combustor outlet conditions. This work is the continuation of a previous activity that revealed the capabilities of unsteady CFD to improve the prediction of flow field and film-cooling adiabatic effectiveness. The comparison is herein extended to heat transfer, to highlight the benefits of combustor-turbine conjugate simulations, in addition to address the impacts on vanes heat load due to highly swirled rather than uniform inlet flow fields.