The Impact of Modeling Assumptions on the Hot Spots Convection Within a Cooled High-Pressure Turbine Stage

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TitleThe Impact of Modeling Assumptions on the Hot Spots Convection Within a Cooled High-Pressure Turbine Stage
Publication TypeJournal Article
Year of Publication2025
AuthorsGiannini G, Pinelli L, Pacciani R, Arnone A, Bertini F, Spano E, Marconcini M
JournalAerospace Science and Technology
Volume166
Number110612
Date Published07-2025
ISSN Number1626-3219
KeywordsAeronautical turbine aerodynamics, combustor-HPT interaction, Helicity, Hot-streaks, URANS
Abstract
To reduce pollutant emissions, modern aeroengines adopt combustors that work with lean premixed flames. These generate significant flow distortions, and due to the compact engine architecture, combustor-turbine interaction becomes a crucial design aspect. From an industrial perspective, achieving design targets while minimizing time to market requires effective and efficient design tools.
This study employs a state-of-the-art in-house CFD solver, extensively validated for combustor-turbine interaction, to investigate the aerodynamics of an engine-representative high-pressure turbine (HPT) stage tested in the DLR NG-Turb facility within the European FACTOR project. The test case consists of a 1.5 stage cooled transonic turbine, with distorted inlet conditions coming from  a combustor simulator.
In detail, steady/unsteady RANS (Reynolds-Averaged Navier-Stokes) simulations were carried out to analyze two clocking positions between the swirling hot spot and nozzle guide vanes (leading-edge clocking, passage clocking). Numerical setups combined Roe’s upwind, central difference, and AUSM+-up schemes with high-Reynolds Wilcox k-omega  and Menter k-omega SST turbulence models, both in baseline and helicity-corrected formulations.
Comparison with experimental data shows that time-accurate simulations improve flow-field predictions downstream of the rotor and that the helicity-based correction can significantly enhance the results. To the best of the author’s knowledge, this is the first application of helicity-corrected turbulence models in the context of hot-streak interaction with an aeronautical cooled HPT stage.
This work demonstrates that URANS simulations with advanced turbulence closures can effectively estimate the complex aerodynamics of realistic HPT and hot-streaks migration, while ensuring computational requirements that are in line with industrial design practices.
URLhttps://www.sciencedirect.com/science/article/pii/S1270963825006832
DOI10.1016/j.ast.2025.110612
Refereed DesignationRefereed