Can jet noise be predicted using linear instability wavepackets?

Abstract

According to a recent hypothesis corroborated by experimental investigations, large-scale coherent structures in turbulent jet flows can be modelled as wavepackets. This conjecture suggests that these structures can be responsible for low-frequency acoustic radiation. In this contribution, we compute optimally forced stability wavepackets, based on mean flow data of a turbulent jet. The dataset is obtained from fully compressible DNS. The final aim is to assess the validity of the hypothesis by verifying to what extent the jet noise can be predicted by means of these linear structures.