摘要: The current preliminary study initiates complementary experimental and numerical efforts to re-examine resonant feedback mechanism of flow-acoustic interactions in airfoil transitional boundary layers and its contribution to low-s... 展开 The current preliminary study initiates complementary experimental and numerical efforts to re-examine resonant feedback mechanism of flow-acoustic interactions in airfoil transitional boundary layers and its contribution to low-speed airfoil trailing-edge noise. Furthermore, the impact of impinging vortical flow disturbances and the corresponding interaction of leading and trailing edge noise sources is considered. Recorded unsteady responses of loaded, transitional NACA0012 airfoil with tripped suction or pressure sides indicate the presence of shifted ladder-type tonal structures with dual velocity dependence in the acoustic signal previously reported in the literature. The installation of upstream grid generating low-intensity turbulence appears to eliminate the feedback mechanism leaving just a single velocity dependence for the dominant spectral components. Numerical efforts employ a high-order Navier-Stokes solver implementing low-pass filtering of poorly resolved high-frequency solution content to retain numerical accuracy and stability over the range of flow regimes. Upstream flow disturbances are introduced inside the computational domain through a source term in the momentum equations. 收起