Wall-Resolved Large Eddy Simulation for Aeroengine Aeroacoustic investigation

摘要

The work presented here forms part of a larger project on Large-Eddy Simulation (LES) of aeroengine aeroacoustic interactions. In this paper we concentrate on LES of near-field flow over an isolated NACA0012 airfoil at zero angle of attack and a chord based Reynolds number of Re_c = 2×10~5. A wall-resolved compressible numerical Large Eddy Simulation (NLES) approach is employed to resolve streak-like structures in the near-wall flow regions. The calculated unsteady pressure/velocity field will be imported into an analytically-based scheme for far-field trailing edge noise prediction later. The boundary layer mean and root-mean-square (rms) velocity profiles, the surface pressure fluctuation over the airfoil, and the wake flow development are compared with experimental data and previous computational simulations in our research group. It is found that the results from the wall-resolved compressible NLES are very encouraging as they correlate well with test data. The main features of the wall-resolved compressible NLES, as well as the advantages of such compressible NLES over previous incompressible LES performed in our research group, are also discussed.