Modelling and control of noise in a flexible flow duct

Stability and control of noise in a flow duct are discussed in this paper. The flow is assumed to be uniform for the steady state. But an unstationary interaction between acoustic waves and a flexible part of the wall can induce wave amplification up to an instability. This phenomenon is similar to flutter encountered in aeroelasticity of airfoils [H. Dowell, C. Curtiss Jr., R.H. Scanlan, F. Sisto, A Modern Course in Aeroelasticity, Kluwer Academic Publishers, 1989; Y.C. Fung, An Introduction to the Theory of Aeroelasticity, J. Wiley, New York, 1955]. In fact, one can suggest that the flexible wall can act as a trap for acoustic energy and using a smart device located on this structure, one can design an efficient control method for noise. The goal of this paper is to describe a simple model and few numerical tests which partially justify these considerations.