Broadband trailing-edge noise prediction with a stochastic source model

Abstract

A RANS-based numerical technique for the prediction of the airfoil trailing-edge broadband noise is presented. The definition of the sound sources from RANS turbulence statistics is based on a stochastic reconstruction of the turbulent velocity fluctuations. The method, named Eulerian Solenoidal Digital Filter, accounts for the convective transport and for the solenoidality of the velocity field. The acoustic near field is computed solving the Acoustic Perturbation Equations in the frequency domain. The integral formulation of Ffowcs Williams and Hawkings is used to evaluate the far-field radiation. The ESDF method is validated for the case of homogeneous isotropic turbulence and it is applied to the calculation of the broadband trailing-edge noise of a NACA 0012 airfoil. Near-field and far-field results are compared with analytical and experimental data.