Multitube pilot injector having an insulated manifold for a gas turbine combustor

A combustor for a gas turbine engine and comprising:

• a generally cylindrical flow sleeve;
• a generally cylindrical combustion liner positioned radially inward from the flow sleeve and defining a combustion zone;
• a first injector that is generally annularly shaped and surrounds the combustion liner and is positioned at a downstream end of the flow sleeve, the first injector comprising:
• radially outward openings to allow passage of compressed air following a radially outward path;
• radially inward openings to allow passage of compressed air following a radially inward path;
• and
• a second injector that is positioned radially inward of the combustion liner at an inlet end of the combustion zone to receive the compressed air from the radially outward openings in the first injector following the radially outward path, the second injector comprising:
• a plurality of air/fuel mixing tubes including a radially outer subset of air/fuel mixing tubes and a radially inner subset of air/fuel mixing tubes;
• a first fuel manifold in fluid communication with the radially outer subset of air/fuel mixing tubes;
• and
• a second fuel manifold in fluid communication with the radially inner subset of air/fuel mixing tubes;
• and
• a plurality of static air plenums, each static air plenum surrounding a corresponding one of the plurality of air/fuel mixing tubes such that each air/fuel mixing tube is thermally isolated from the respective fuel manifold via the corresponding static air plenum.