A combustor includes at least one combustor liner defining a combustion chamber capable of directing combustion products toward a turbine. At least one combustor sleeve is located outside of the combustion chamber and is capable of reducing a magnitude of acoustic waves in the combustion chamber. The at least one combustor liner and the at least one combustor sleeve define at least one flow channel therebetween. Further, a combustor includes at least one combustor liner defining a combustion chamber capable of directing combustion products toward turbomachinery. At least one combustor sleeve disposed outside of the combustion chamber and is capable of controlling distribution of fluid flow in the combustor to modify a uniformity of the fluid flow to the combustion chamber.