Causality and intrinsic thermoacoustic instability modes

Emilien Courtine (1) , Laurent Selle (1) , Franck Nicoud (2) , Wolfgang Polifke (3) , Camilo Silva (3) , Michaël Bauerheim (4) , Thierry Poinsot (1)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 I3M - Institut de Mathématiques et de Modélisation de Montpellier
3 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
4 CERFACS - Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique

Direct numerical simulation of a confined laminar premixed flame has been performed in an anechoic combustor, showing self-sustained intrinsic thermoacoustic oscillations. Theoretical predictions based on acoustic jump relations and the n − τ model for the flame are presented and causality concerns are discussed. The instability’s frequency and mode structure are recovered numerically with very good accuracy. A detailed discussion on the interplay of the physical phenomena responsible for this dynamical coupling is also carried out.

Mots clés: Intrinsic modes; Instabilities; Combustion; Causality

Domaines: Acoustique [physics.class-ph]; Thermique [physics.class-ph]

Emilien Courtine, Laurent Selle, Franck Nicoud, Wolfgang Polifke, Camilo Silva, et al.. Causality and intrinsic thermoacoustic instability modes. CTR - Summer Program, Jul 2014, Stanford, United States. pp.169-178. ⟨hal-02166756⟩