Mathematical model for the initiation of intense acoustic vibrations in a ramjet ejector combustor and their suppression by resonators

A mathematical model is constructed to describe the mechanism of intense acoustic vibrations in a ramjet ejector combustor based on the instability of natural acoustic vibrations in the combustor due to jet exhaust. The feedback necessary for the onset of instability of acoustic waves is taken to be their interaction with the unsteady gas motion induced by the vortex sheet from the trailing edges of the combustor. An algorithm for suppressing intense acoustic vibrations in the combustor using resonators is developed. The obtained theoretical results are compared with the results of experimental studies.