Fuel-air mixture distribution for gas turbine engine combustors

摘要

A method of noise control from a combustor of a gas turbine engine includes selectively forming a plurality of local circumferential zones with different fuel-air ratios within the combustor.

主权项

1. A fuel system for a gas turbine engine comprising:
a plurality of duplex fuel nozzles; a plurality of simplex fuel nozzles, wherein said plurality of duplex fuel nozzles and said plurality of simplex fuel nozzles are arranged in alternating groups in a combustor and circumferentially around a central engine axis, said alternating groups defining local circumferential zones in said combustor; a primary fuel manifold operable to communicate fuel to a primary flow jet in each of said plurality of duplex fuel nozzles; a secondary fuel manifold operable to communicate fuel to a secondary flow jet in each of said plurality of duplex fuel nozzles and a secondary flow jet in each of said plurality of simplex nozzles; a flow divider valve operable to proportion fuel flow to said primary fuel manifold and said secondary fuel manifold; and an equalizer valve downstream of the flow divider valve and in communication with said primary fuel manifold and said secondary fuel manifold, said equalizer valve movable between an open position and a closed position, said closed position operable to permit supply of said primary fuel manifold with greater fuel pressure than said secondary fuel manifold and said open position operable to permit supply of said primary fuel manifold with essentially an equal fuel pressure as said secondary fuel manifold such that different fuel-air ratios are provided to said local circumferential zones.