Patent ID: 8910483

Claim:
A lean premix burner for a gas-turbine engine, comprising: an annular center body having a conically flaring fuel film applicator; an annular fuel distribution chamber; at least one annular fuel channel for receiving fuel from the annular fuel distribution chamber and supplying fuel to a radially inner surface of the fuel film applicator and a radially outer surface of the fuel film applicator, or to the radially outer surface of the fuel film applicator; a first annular air duct having a first swirler element positioned on an outer circumference of the annular center body; a second annular air duct having a second swirler element positioned on an inner circumference of the annular center body; a V-shroud flame stabilizer at least partially positioned within the inner circumference of the annular center body; a pilot fuel injector positioned radially inwardly of the V-shroud flame stabilizer; a fuel prefilmer lip attached to the fuel film applicator and configured to extend downstream beyond an adjacent wall of a combustion chamber wall into a combustion chamber of the gas-turbine engine, at least a portion of the fuel prefilmer lip being the most downstream portion of the lean premix burner, an entirety of the V-shroud flame stabilizer positioned upstream of the most downstream portion of the fuel prefilmer lip; wherein a flow area of the first annular air duct downstream of the first swirler element and upstream of a free end of the fuel prefilmer lip decreases with respect to a flow area of the first swirler element to accelerate air flowing in the first annular duct, and a flow area of the second annular air duct downstream of the second swirler element and upstream of the free end of the fuel prefilmer lip decreases with respect to a flow area of the second swirler element to accelerate air flowing in the second annular duct, the flow area of the second annular air duct steadily decreasing past and substantially downstream of the at least one annular fuel channel to steadily accelerate the air flowing in the second annular duct past and substantially downstream of the at least one annular fuel channel, the accelerated air in each of the annular ducts being imparted with swirl directions to act upon a fuel film of the fuel film applicator corresponding to a flow direction of the fuel film.