ZONAL DETACHED-EDDY SIMULATION APPROACH VS. URANS FOR THE PREDICTION OF THE FLOW FIELD THROUGH A LOW PRESSURE VANE LOCATED DOWNSTREAM OF A TRANSONIC HIGH PRESSURE TURBINE

The present work aims at studying the aerodynamic flow field within the first Low Pressure Vane (LPV) located downstream of a transonic High Pressure Turbine (HPT). A Zonal Detached-Eddy Simulation (ZDES) which is an hybrid URANS (Unsteady Reynolds Averaged Navier-Stokes)-DES approach, appears as a good alternative in terms of computational cost and quality of turbulent phenomena description when it comes to the capture of key parameters of losses generation in a LPV. ZDES is used on the LPV and the unsteady periodic flow field coming from the upstream HPT is modelled through a nonuniform rotating inlet boundary condition. The result is compared to a URANS simulation carried out with the same mesh and numerical parameters: this enables to quantify the differences and to state on the benefit of an advanced turbulent approach. Turbulent mechanisms are assessed with the computation of the power spectral density at different locations in the domain. To complete the analysis, the two numerical predictions are compared to experimental data. Wakes and vortices evolutions are studied in detail making it possible to put them into perspective with the aerodynamic losses generated in the LPV.