Numerical Study of a High-Pressure Turbine Stage with Inlet Distortions

The study of inlet flow distortion (hot streaks and entropy waves) propagation through high-pressure turbine (HPT) stages is an open topic for aero-engine design, due to their multiple effects on aerodynamics, heat exchange and noise generation. The request to design compact and lightweight systems has recently led to a reduction of the combustor-turbine axial gap, making the interaction between the HPT and the combustor extremely critical. For this reason, the main aim of the present work is to numerically study how different clocking positions between temperature distortions and stator vanes can affect the evolution of hot streaks and entropy waves. In order to validate the numerical results, experimental data coming from an un-cooled high-pressure gas turbine stage tested at the Laboratorio di Fluidodinamica delle Macchine (LFM) of the Politecnico di Milano (Italy) has been used. The good agreement between numerical results and experimental data confirms the accuracy of the approach based on the CFD TRAF code and suggests recommendations for the design of the following rows.