Prediction of the far-field jet noise using Kirchhoff's formulation

Computational aeroacoustics is concerned with the prediction of the aerodynamic sound source and transmission of the generated sound starting from the time dependent governing equations. The Kirchhoff method is used as an alternative to the acoustic analogy approach. It assumes that the sound transmission is governed by a simple wave equation. It also consists of the calculation of the nonlinear near- and mid-field with the far-field solutions found from a linear Kirchhoff formulation evaluated on a surface surrounding the nonlinear field. Application of this method to a subsonically moving surface and employing the frequency domain formulation is discussed.