Towards an efficient detection of hydrodynamic-acoustic feedback mechanisms in an industrial context

Direct noise computation (DNC) offers some advantages compared to hybrid approaches in simulating aeroacoustic mechanisms. In DNC, hydrodynamics and acoustics are solved in a coupled manner which allows to depict intricate interactions between both fields. However, this approach intrinsically requires the resolution of the occurring disparate length and time-scales. Our open-source Discontinuous Galerkin framework FLEXI, has been successfully applied to this multiscale problem. The aim of this paper is to draw the attention to an effcient method for the detection of aeroacoustic feedback. Aeroacoustic feedback can be effectively predicted by a global stability analysis. Here, an impulse response analysis on a time averaged flow field is carried out. The underlying baseflow is maintained constant through volume forcing terms. To overcome the drawback of long time-averaging of LES-data, the question arises if a computationally less expensive numerical method, ideally a RANS-solver, can be employed to generate the time-averaged baseflow which is then used by FLEXI to simulate the response of small perturbations. Results of a side-view mirror will demonstrate the advantages of the latter approach. In summary, this paper will introduce an e cient method to depict aeroacoustic feedback within our framework FLEXI with regard to future industrial use.