Large Eddy Simulation of Airfoil Self-noise using OpenFOAM

Large-eddy simulation (LES) of near-field flow over a NACA6512-63 airfoil at zero angle of attack with boundary layer trip was carried out using OpenFOAM® CFD code. The experimental chord based Reynolds number is Re = 1.9 × 105; the corresponding inlet flow velocity is 21.11 m/s. The airfoil was tripped on both sides in the experimental setup to remove the extraneous Tollmien-Schlichting (TS) noise source, which has been incorporated into the numerical grid of the LES as simplified step trip geometry. For better comparison with the experimental measurements, the large eddy simulation includes the wind-tunnel installation effects by using appropriate inflow boundary conditions obtained from the RANS 푘−휔 푆푆푇 simulation of the whole wind tunnel domain. Far-field noise predictions was achieved by integral method based on Curle’s acoustic analogy, as implemented in OpenFOAM. Calculated mean and unsteady flow results compared well with published experimental data. The predicted sound pressure levels agree very well with the experimental results at low to medium frequency range.