Methods for transfer matrix evaluation applied to thermoacoustics

Flavio Bannwart , Guillaume Penelet (1) , Pierrick Lotton (1) , Jean-Pierre Dalmont (1)

1 LAUM - Laboratoire d'Acoustique de l'Université du Mans

The design of a thermoacoustic (TA) prime-mover partly relies on the knowledge of its onset conditions, i.e. the resonance frequency of the self-sustained oscillations and the minimum heat power supply which is necessary for the outbreak phenomenon. These onset conditions can be calculated once the transfer matrix of the TA core is determined, whichever by analytical modeling or acoustic measurements. The latter, however, consists in an interesting option to avoid thermophysical or geometrical considerations of complex structures, mainly with respect to the TA regenerator, as the TA core is treated as a black box. Two experimental methods are considered in this work: the Two Loads Method and the Impedance Method. These methods are here presented, discussed and compared on several aspects, taking into account simulated and experimental results for a stack and a regenerator submitted to a steep temperature gradient. Regarding these aspects of investigation, the Two Loads Method was proved to be the best for the stack, meanwhile the Impedance Method for the regenerator. In the second case, important experimental difficulties arise due to intrinsic properties of the regenerator. Therefore, the Impedance Method was conceived towards the investigation into this specific problematic and has succeeded on its purpose.

Domaines: Acoustique [physics.class-ph]

Flavio Bannwart, Guillaume Penelet, Pierrick Lotton, Jean-Pierre Dalmont. Methods for transfer matrix evaluation applied to thermoacoustics. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810873⟩