THEORETICAL AND EXPERIMENTAL INVESTIGATIONS ON DAMPERS PERFORMANCES FOR SUPPRESSION OF THER-MOACOUSTIC OSCILLATIONS

摘要

This study deals with a generic approach for prediction of pulsation suppression with acoustic dampers. Although the theory is valid for any self-oscillating system and for any damper type, the focus in this paper is on suppression of thermoacoustic oscillations using Helmholtz dampers. The developped theory has been validated using a novel experimental method. In thermoacoustics the constructive interference between the heat release and the acoustic field is responsible for growth of acoustic amplitudes. In the newly developed measurement method, this interaction has been mimicked by a feedback excitation using loudspeakers and microphones. The theory was supported by non-linear time-domain acoustic network simulations and found to be in excellent agreement with the validation experiments.