A turbomachine includes a compressor, a turbine operatively coupled to the compressor, and a combustion assembly fluidly linking the compressor and the turbine. The combustion assembly includes at least one injector having a burner tube including an outer wall portion and an inner wall portion that define a mixing zone. A swirler arranged within the mixing zone. The swirler includes a plurality of vanes, with at least one of the plurality of vanes having a wall section including an outer surface and an inner surface that define a hollow interior portion. An insert member is arranged within the hollow interior portion. The insert member includes at least one guide element that is disposed and configured to deliver a fluid flow to the hollow interior portion to flow over the wall section of the at least one of the plurality of vanes.
FEDERAL RESEARCH STATEMENT
 This invention was made with Government support under Contract No. DE-FC26-05NT42643, awarded by the US Department of Energy (DOE). The Government has certain rights in this invention.