LAUSR

ABSTRACT This paper studies the effect of mean flow, temperature ratio and area ratio of a dump combustor on combustion instability. From an explicit transfer function representation of combustor acoustics, it is shown that mean flow has an effect of scaling reflection coefficients and that combustion instability can be determined from roots of a scalar equation having two key parameters; temperature and area ratios. As a special case, we present a general condition for the occurrence of intrinsic thermo-acoustic modes for a non-zero mean flow. Our theoretical findings are validated with experimental data in literature.