In order to obtain influence of acoustic resonators on the acoustic characteristic of combustors

a model combustor with axial resonators was investigated experimentally in cold flow tests. The length

area ratio (section area of acoustic resonators divided by section area of combustor) and number of acoustic resonators were changeable in the experiments. It was found that the eigen frequencies of combustor decreased as the length of acoustic resonators increased. The results show that there exists an optimal acoustic resonator length for restraining 1T mode

which is independent from area ratio of acoustic resonators and a little smaller than quarter wave length of 1T mode. For restraining 1T mode

there also exists an optimal area ratio

which is 0.17 in present study. This also indicates that the distribution of acoustic resonators can dramatically affect the acoustic characteristic of a combustor

with acoustic wave decaying faster for more resonators at the same area ratio.