Application of an Overset Grid Method to the Large Eddy Simulation of a High-Speed Multistage Axial Compressor

The present study aims at evaluating the feasibility and the accuracy of the Large-Eddy Simulation of an actual high-pressure multistage compressor, performed with the TurboAVBP numerical method. TurboAVBP relies on the coupling of several domains via an overset grid method. The latter is demonstrated to keep the order of accuracy of the numerical scheme across six successive rotor-stator interfaces. The simulated configuration corresponds to the 3.5 stage axial compressor CREATE. Three unstructured grids of CREATE, with different resolutions, are generated. They contain 37 blades, the actual rotor tip clearances and a recirculating cavity. The predictions of the global aerodynamic performances and of the radial profiles are found to agree well with experimental data. The analysis of the flow shows that the finest grid exhibits the turbulent flow structures expected in such a configuration, including the blade and vane wakes and the rotor tip leakage vortices.