A system for tuning a combustor of a gas turbine includes a flow sleeve having an annular main body. The main body includes an upstream end, a downstream end, an inner surface and an outer surface. A cooling channel extends along the inner surface of the main body. The cooling channel extends at least partially between the downstream end and the upstream end of the main body.
FEDERAL RESEARCH STATEMENT
 This invention was made with Government support under Contract No. DE-FC26-05NT42643, awarded by the Department of Energy. The Government has certain rights in this invention.