Abstract
Flow structures around a NACA0012 wingtip are investigated using a zonal LES/RANS hybrid method in order to understand the noise generation mechanism around the flap-edge. It is known from previous studies that the flow around a blunt wingtip is similar to that of the flap-edge. Grid dependency studies are performed for both time-averaged and unsteady components, and the results are assessed via comparison with the experimental data. It became apparent that the zonal LES/RANS hybrid results are more sensitive to the chordwise grid resolution, compared with these of RANS. Based on the validated data, the noise generation mechanism around the wingtip is discussed. The near-field flow structures relevant to noise generation are obtained successfully.
