Receptivity and aeroacoustic resonance in channels with blowing walls

Abstract

In this article, the creation of instability waves by acoustic waves in the two-dimensional Taylor flow developing in channels with blowing walls is studied. The receptivity of the flow to a localized defect of injection velocity is investigated by assuming normal mode form of the instabilities thanks to a theory of Hill [J. Fluid Mech. 292, 183 (1995)] based on adjoint methods. The results show good agreement with direct numerical simulations. A mechanism of aeroacoustic resonance is numerically put in light which involves the receptivity process together with the creation of acoustic waves by instability waves passing through a surface at constant pressure. Theoretical predictions of the temporal growth or damping rate of both acoustic and instability waves give satisfactory results. Discussion about experimental results available from the so-called VECLA facility is finally provided.