Trailing edge noise prediction based on wall pressure spectrum models for NACA0012 airfoil

This paper compares several approaches for the prediction of the noise emitted by a NACA0012 airfoil at 0∘ and 4∘ of angle of attack and a Reynolds number Re=1.5×106. Amiet's semi-analytical model for trailing-edge noise is combined with two-dimensional Reynolds-Averaged Navier-Stokes (RANS) computations. The wall-pressure spectrum, which constitutes the cornerstone of Amiet's model, is obtained by processing the boundary layer data extracted from the simulations. The specific contribution of the paper is a comparison of two families of prediction methods: semi-empirical wall-pressure models that are fitted to experimental databases, and statistical approaches based on the integration of the Poisson equation across the boundary layer profile. The semi-empirical models that were calibrated on airfoil databases provide better predictions with experiments, while the models based on flat-plate boundary layer data fail to reproduce the measured spectra. Considering the statistical approach, it was shown to predict the general spectral features, but with an overall under-prediction of about 3 dB. It can be concluded from this study that the statistical approach proves indeed more robust than semi-empirical models when the latter were not precisely calibrated for the flow under consideration. Further improvements of the statistical approach are suggested for future work.