Micromixer Heat Shield

Methods and systems are provided for operating a turbine engine. The combustor includes a combustor wall defining a combustion zone (210) and a fuel nozzle (200). The fuel nozzle includes a forward face (220), an aft face (230) downstream from the forward face and adjacent to the combustion zone, a plurality of mixing tubes (320) extending between the forward face and the aft face, an outer sleeve (240) positioned radially outward of the plurality of mixing tubes, a heat shield (260) positioned radially inward of the outer sleeve, and a baffle plate (300) between the forward face and the aft face. At least one of the plurality of mixing tubes includes a sidewall (350) that includes an injection opening (360) defined therethrough. The baffle plate is oriented to channel fuel between the plurality of mixing tubes and between the baffle plate and the aft face prior to the fuel being channeled through the injection opening.