Global linear stability analysis of flow in a lined duct

Lucas Pascal (1) , Estelle Piot (1) , Grégoire Casalis (1, 2)

1 ONERA - The French Aerospace Lab [Toulouse]
2 ISAE-SUPAERO - Institut Supérieur de l'Aéronautique et de l'Espace

Eigenmodes of the linearised Euler equations are computed in order to study lined flow duct global stability. A simplified configuration is considered and the governing equations are discretised by means of the discontinuous Galerkin method. A biorthogonal technique is used to decompose the global eigenfunctions into local eigenmodes. The system dynamics switches from noise amplifier to resonator as the length of the liner is increased. The global mode in the liner region is shown to be mainly composed of a hydrodynamic unstable wave and a left-running acoustic mode.

Mots clés: Acoustics; Global stability; Lined duct; Discontinuous Galerkin

Domaines: Acoustique [physics.class-ph]

Lucas Pascal, Estelle Piot, Grégoire Casalis. Global linear stability analysis of flow in a lined duct. Journal of Sound and Vibration, 2017, vol. 140, pp. 19-34. ⟨10.1016/j.jsv.2017.08.007⟩. ⟨hal-01697793⟩