16th AIAA/CEAS Aeroacoustics Conference, June 7-9, 2010, Stockholm, Sweden. Numerical Simulation of Sound from Flow over an Airfoil with a Blunt Trailing Edge  Phoi-Tack Lew  , Alireza Najafi-Yazdi  & Luc Mongeau  Department of Mechanical Engineering, McGill University, Montreal, QC H3A 2K6, Canada The objective of this study was to investigate the sound generated by flow over an airfoil with a blunt trail- ing edge. Numerical simulations were performed using the Lattice-Boltzmann Method (LBM) with the Very Large-Eddy Simulation (VLES) approach. The distinct advantage of LBM over other Navier-Stokes based computational fluid dynamics (CFD) methods lies in its ease of handling problems with complex geometries. A 3-D simulation over a 45 o asymmetric blunt trailing edge with a freestream Mach number of M 1 D 0:09 and Re c D 1:85  10 6 was performed. Comparisons were made with detailed experimental data for validation. A computed shedding frequency of f LBM D 215 Hz was obtained. The measured frequency was f exp D 219 Hz. The discrepancy could be attributed to differences between the experimental and numerical setup. The far-field noise was predicted using both the solid and porous Ffowcs Williams-Hawkings (FWH) surface inte- gral acoustic method. The far-field spectra showed good agreement with experiments up to the grid cut-off frequency. Nomenclature Roman Symbols a 1 Ambient Speed of Sound c Chord length c i Particle speed f Frequency (Hz) f i Distribution function f eq i Equilibrium distribution function h c Airfoil thickness M 1 Mach number = U 1 =a 1 SPL Overall sound pressure level p pressure R Radial arc length from tip of trailing edge Re c Reynolds number = U 1 c= 1 Sr Strouhal number = 2f y f =U 1 T Lattice temperature t Time U 1 Freestream velocity w i Weight parameter for lattice model x;y Cartesian coordinates x s Separation location y f Wake thickness parameter x Cartesian coordinate of fluid particle Greek Symbols  Presented at the 16th AIAA/CEAS Aeroacoustics Conference, June 8th, 2010, Stockholm, Sweden.  Post-Doctoral Research Associate, AIAA Member  Research Assistant, AIAA Student Member  Professor, Senior Member AIAA. Copyright c  2010 by P. Lew, A. Najafi-Yazdi and L. Mongeau. All other rights are reserved by the copyright owner. 1 of 20 American Institute of Aeronautics and Astronautics Paper 2010-3879 16th AIAA/CEAS Aeroacoustics Conference AIAA 2010-3879 Copyright © 2010 by P. Lew, A. Najafiyazdi and L. Mongeau. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.