Abstract: A fuel-air mixer for a gas turbine engine combustor having a primary swirler and a venturi that effectively reduces carboning via purge air. Purge air flows axially through the fuel-air mixer forming a boundary layer of air on the inner surface of the venturi. The boundary layer of air minimizes the amount of fuel contacting the inner surface of the venturi resulting in reduced carbon resin or coke formation.

Abstract: An annular combustor includes a plurality of circumferentially spaced, radially extending dilution poles disposed in an intermediate zone thereof between a forward combustion zone and an aft combustion zone. Adjacent ones of the dilution poles define therebetween a throat for receiving the combustion gases from the forward zone. The dilution poles include circumferentially facing dilution holes for injecting dilution air into the throats for mixing with the combustion gases being channeled therethrough. The dilution poles are effective for blocking the combustion gases at a plurality of circumferentially spaced apart locations and accelerating the combustion gases through the throats for reducing residence time in the throat. The dilution air is injected through the dilution holes for improved penetration into the combustion gases in the throats for mixing therewith to form lean combustion gases which undergo final combustion in the aft zone for reducing NO.sub.x emissions.

Abstract: A method of operating a double dome combustor includes channeling compressed airflow through an inner dome for generating inner combustion gases having an inner reference velocity greater than an outer reference velocity of outer combustion gases generated from compressed airflow channeled through an outer dome, and diffusing the outer and inner combustion gases in outer and inner combustion zones. One double dome combustor effective for practicing the method in accordance with the present invention includes outer and inner combustor liners and domes, with the domes having outer and inner carburetors disposed therein, respectively. The inner carburetors are sized for generating inner combustion gases in the inner combustion zone having an inner reference velocity greater than an outer reference velocity of the outer combustion gases generated in the outer combustion zone.

Abstract: A combustion assembly includes a combustor having inner and outer liners, and pilot stage and main stage combustion means disposed between the liners. A turbine nozzle is joined to downstream ends of the combustor inner and outer liners and the main stage combustion means is close-coupled to the turbine nozzle for obtaining short combustion residence time of main stage combustion gases for reducing NO.sub.x emissions. In a preferred and exemplary embodiment of the invention, the combustion assembly includes first and second pluralities of circumferentially spaced fuel injectors and air swirlers disposed radially outwardly of a plurality of circumferentially spaced hollow flameholders having fuel discharge holes. Pilot stage combustion is effected downstream of the first and second fuel injectors and swirlers, and main stage combustion is effected downstream of the flameholders.

Abstract: A gas turbine engine carburetor including an annular swirler and a new and improved fuel injector cooperating therewith is disclosed which is effective for providing low BTU gaseous fuel to a combustor. The swirler includes a plurality of circumferentially spaced swirler vanes effective for channeling air along an annular inner surface of the swirler. The fuel injector includes a hollow injector tip having an aft portion including a plurality of circumferentially spaced outlet apertures disposed in an outer surface thereof. The outer surface is aligned obliquely to a longitudinal centerline axis of the injector tip and the swirler.