SIMULAZIONI AD ALTA FEDELTA' DEL ROTORE DEL COMPRESSORE CME2

This work is the product of the internship at ONERA (Office National d’Etudes et de Recherches Aérospatiales) for a period of 5 months. This end-of-study internship is the conclusion of the Master 2 in Engineering of Energy Conversion Machines, course "Energy and Environment" at the École Nationale Supérieure d’Arts et Métiers (ENSAM) ParisTech. The objective of this study is to analyse the flow developing in the rotor of the CME2 axial compressor (Compressor Mono-Étage), using high-fidelity numerical simulations. In particular, the aim is to implement and analyse a campaign of numerical tests to reproduce the rotating stall, a highly unstable aerodynamic phenomenon that occurs at low flow rates in the compressor. Steady RANS (Reynolds Average Navier Stokes) simulations are first carried out, then, in a second phase, thanks to the RANS results, unsteady ZDES (Zonal Detached Eddy Simulation) simulations are implemented. The tool used is elsA (Ensemble Logiciel de Simulation en Aerodynamique), the ONERA-Safran property multi-purpose aerodynamic calculation software platform. A single rotor channel is simulated in RANS first on a coarse structured mesh, then on a coarse unstructured mesh, and finally, a refinement of the mesh is performed to adapt the case for ZDES simulation. The results are analysed by comparing fluid-dynamic variables of the flow at stable operating points and unstable ones at low flow rates. Comparisons are also made with previous studies carried out, present in the literature. Finally, the overall objective is to better understand the phenomenon of rotating stall and to show that numerical simulation is well adapted to model unsteady phenomena.