Numerical analysis of sound generating mechanisms of a high-lift device

In this study the flow field and the acoustic field over a high-lift configuration consisting of a deployed slat and a main wing is numerically analyzed. The flow parameters are Ma = 0.16, Re = 1.4 * 10(6), alpha(Slat) = 23 degrees and alpha(geo) = 13 degrees. The flow data, which are computed via a large-eddy simulation, provide the distributions being plugged in the source terms of, e.g. the acoustic perturbation equations (APE) or the Ffowcs-Williams and Hawkings (FWH) equation, to compute the acoustic near field. The analysis shows the interaction of the shear layer of the slat trailing edge and the slat gap flow to generate higher vorticity than the main airfoil trailing edge shear layer. Thus, the slat gap is the dominant noise region.