Numerical study of head-on blade-vortex interaction noise

A numerical study is accomplished to investigate the far-field head-on blade-vortex interaction (BVI) noise. The Reynolds-averaged Navier-Stokes equations are used to simulate the phenomenon of the BVI. They are solved with the modified Osher-Chakravarthy’s finite volume scheme which is third-order accurate in space and second-order in time. The far-field noise is analyzed by the Kirchhoff’s method. Therefore only the near- and mid-field solutions are necessary to be solved precisely, as for the far field informations, they can be calculated from the near- and mid-field solutions. Comparisons of two turbulence models, the Baldwin-Lomax model and the Johnson-King model, are presented. It is demonstrated that when the free stream Mach number is lower than 0.755 approximately for NACA0012 airfoil, the Baldwin-Lomax model can have acceptable results. Numerical tests, flat plate boundary layer and NACA0012 airfoil flowfields, are presented to demonstrate the accuracy and merits of the scheme studied. During the BVI process, acoustic wave is generated and the most loud region is found below the airfoil.