Surface Integral Analogy Approaches to Computing Noise Generated by a 3D High-Lift Wing Configuration

Three surface integral approaches of the acoustic analogies are studied to predict the noise from a three-dimensional, high-lift wing configuration. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings method of the permeable integral surface and the Curle method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specifically from the pressure perturbation on the wall. A new way to construct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex objective – the actual wing with high-lift devices – the integral surface based on the vorticity is constructed to follow the flow structures. The noise from the core flow region is based on the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FWH formulation. The role of each wall component on noise contribution is analyzed using the Curle method. The results of the three methods are then compared