Premixer array

An annular mixer for a gas turbine engine, the annular mixer being located directly upstream, in a flow direction, of a combustion section of the gas turbine engine, such that, during operation of the gas turbine engine, the annular mixer provides a pilot fuel and a fuel-air mixture to the combustion section, the annular mixer comprising:

• a plurality of premixer arrays arranged in a circumferential direction of the annular mixer, the plurality of premixer arrays defining an A-Zone, a B-Zone, and a C-Zone of the annular mixer that each extend in the circumferential direction with the A-Zone being adjacent to an outer liner of the combustion section, the B-Zone being disposed radially inward of the A-Zone along a radial direction, and the C-Zone being disposed radially inward of the B-Zone along the radial direction and adjacent to an inner liner of the combustion section, each premixer array of the plurality of premixer arrays comprising:
• a premixer array mounting plate coupled to a bulkhead wall of the combustion section that extends between the inner liner and the outer liner, the premixer array mounting plate defining a plurality of tube ports extending therethrough, the plurality of tube ports being disposed in each of the A-Zone, the B-Zone, and the C-Zone;
• one or more pilot fuel tubes coupled to the premixer array mounting plate via one or more pilot tube ports of the plurality of tube ports and configured to provide the pilot fuel to the annular mixer;
• one or more non-swirled premixer tubes coupled to the premixer array mounting plate via one or more non-swirled premixer tube ports of the plurality of tube ports and configured to provide the fuel-air mixture to the annular mixer that mixes with the pilot fuel, a first non-swirled premixer tube of the one or more non-swirled premixer tubes being located in the B-Zone, and a second non-swirled premixer tube of the one or more non-swirled premixer tubes being located in the C-Zone adjacent to the first non-swirled premixer tube;
• and
• a plurality of swirled premixer tubes coupled to a plurality of swirled premixer tube ports of the plurality of tube ports and configured to provide the fuel-air mixture to the annular mixer that mixes with the pilot fuel, the plurality of swirled premixer tubes including:
• a first subset of swirled premixer tubes located in the A-Zone and configured to guide the pilot fuel radially outward along the radial direction toward the outer liner of the combustion section, a first pilot fuel tube of the one or more pilot fuel tubes being located in a center of the first subset of swirled premixer tubes;
• a second subset of swirled premixer tubes located in the B-Zone and configured to guide the pilot fuel radially inward along the radial direction toward the first non-swirled premixer tube and the C-Zone;
• and
• a single swirled premixer tube located in the C-Zone and configured to guide the pilot fuel radially inward along the radial direction toward the inner liner of the combustion section.