Effect on burner partitioning on system thermoacoustics

In this paper the thermo-acoustic properties of a system equipped with a segmented burner are investigated. Such segmentation can for example be realized by combining two different burners on the same deck. The study is conducted using finite element and network modelling techniques. It is found that even a small spatial separation of the burner’s sections can lead to significant alteration of the global acoustic behavior of the system. In particular, the location of the eigenmodes and hence the stability of the system can be affected. It is shown that the local modification of the acoustic field in the vicinity of the partitioned burner is the physical reason for this phenomena. This finding poses some limitations on to use of the lumped transfer function decomposition approach to estimate the global burner response of a composite flame/burner.