Hybrid Formulations for Computational Aeroacoustics
* Presenting author
Since the beginning of computational aeroacoustics (CAA) several numerical methodologies have been proposed, each of these trying to overcome the challenges that the specific problems under investigation pose for an effective and accurate computation of the radiated sound. Thereby, hybrid methodologies have been established as the most practical methods, due to the independent treatment of the fluid and the acoustic computations. These approaches are based on three steps: (1) perform unsteady flow computations based on an appropriate turbulence model on a restricted sub-domain (also named source domain); (2) compute with an appropriate model the acoustic sources; (3) perform the acoustic field computation. In these simulations it is generally assumed that insignificant physical effects occur from the acoustic to the fluid field. Within our talk, we will discuss three different approaches: (1) inhomogeneous wave equation of Lighthill based on acoustic sources using the Lighthill tensor as well as the Laplacian of the incompressible flow pressure; (2) aeroacoustic wave equation (AWE) using the second time derivative of the incompressible flow pressure as a source term; (3) perturbed convective wave equation (PCWE) using the acoustic scalar potential and the substantial derivative of the incompressible flow pressure as a source term.