Calculation of Sound Scattering by a Boundary Element Extension of Curle’s Analogy

The aeroacoustical analogy derived by Curle for prediction of the sound resulting from turbulence/body interaction is powerful for low Helmholtz number, i.e. compact region. However, for non-compact case when an incompressible flow is adopted, it yields erroneous result. The present work by combining Curle’s analogy with a BEM compensates the weaknesses of the traditional approach. The validation of this method is performed by comparing the sound produced by the leapfrogging of two rectilinear filament vortices within an infinite two-dimensional straight duct by the acoustic field be obtained using tailored Green’s function based on the non-evanescent duct modes. The flow field is obtained by integrating the reciprocal Biot-Sowart induction of the two spinning vortices. The sound is predicted in frequency domain applying the Curle/BEM approach, shows an excellent agreement with the reference solution