Vortex sound interaction and its application in aerospace propulsion system

It is found that vortex sound interaction can resuh in the energy conversion between pressure wave and vortex wave, and there are some possibilities to exploit such mechanism to suppress various instabilities in aerospace propulsion system, including cascade flutter, rotating stall and combustion instability. To reahze these objectives, one of the key issues is to give more accurate vortex sound interaction models. The present paper will firstly review the recent development of vortex sound interaction models, and then discuss the relevant physics with emphasis on the effect of non-linearity and grazing flow on the impedance of a perforated plate. Finally, a hybrid control strategy for the suppression of combustion instability, including theoretical and experimental results, is introduced based on the active change of wall impedance condition through vortex sound interaction.