Abstract: A gas turbine engine combustor conical-flat heat shield includes an annular conical section extending upstream from and being integral with a flat section with a flat downstream facing surface which may be generally perpendicular to or canted with respect to a centerline. The flat section includes radially outer and inner edges at least one of which is circular and circumscribed about a centerline and circumferentially spaced apart clockwise and counter-clockwise radial edges having an origin on the centerline. A gas turbine engine combustor includes conical-flat heat shields in one or more circular rows arranged in a non-symmetrical or asymmetrical pattern. Two or more groups (A, B, C) of the conical-flat heat shields in the circular rows may be mounted on a domeplate and one or more of the conical-flat heat shields is different in one or more of the groups (A, B, C).

Abstract: A gas turbine engine combustor conical-flat heat shield includes an annular conical section extending upstream from and being integral with a flat section with a flat downstream facing surface which may be generally perpendicular to or canted with respect to a centerline. The flat section includes radially outer and inner edges at least one of which is circular and circumscribed about a centerline and circumferentially spaced apart clockwise and counter-clockwise radial edges having an origin on the centerline. A gas turbine engine combustor includes conical-flat heat shields in one or more circular rows arranged in a non-symmetrical or asymmetrical pattern. Two or more groups (A, B, C) of the conical-flat heat shields in the circular rows may be mounted on a domeplate and one or more of the conical-flat heat shields is different in one or more of the groups (A, B, C).

Abstract: A method for actively controlling fuel flow from a fuel pump to a mixer assembly of a gas turbine engine combustor, where the mixer assembly includes a pilot mixer and a main mixer. The pilot mixer further includes an annular pilot housing having a hollow interior, a primary fuel injector mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing, a plurality of axial swirlers positioned upstream from the primary fuel injector. The fuel flow control apparatus further includes: at least one sensor for detecting dynamic pressure in the combustor; a fuel nozzle; and, a system for controlling fuel flow supplied by the fuel nozzle through the valves. The fuel nozzle includes: a feed strip with a plurality of circuits for providing fuel to the pilot mixer and the main mixer; and, a plurality of valves associated with the fuel nozzle and in flow communication with the feed strip thereof.

Abstract: A combustor swirl cup includes coaxial inner and outer swirlers separated by a tubular centerbody. The centerbody includes a bypass inlet surrounding the inner swirler and diverges aft along a perforate inner nozzle to terminate at an annular flameholder. An impingement ring is spaced forward from the flameholder in flow communication with the bypass inlet for receiving cooling air therefrom to impingement cool the flameholder.

Abstract: An apparatus for actively controlling fuel flow from a fuel pump to a mixer assembly of a gas turbine engine combustor, where the mixer assembly includes a pilot mixer and a main mixer. The pilot mixer further includes an annular pilot housing having a hollow interior, a primary fuel injector mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing, a plurality of axial swirlers positioned upstream from the primary fuel injector. The fuel flow control apparatus further includes: at least one sensor for detecting dynamic pressure in the combustor; a fuel nozzle; and, a system for controlling fuel flow supplied by the fuel nozzle through the valves. The fuel nozzle includes: a feed strip with a plurality of circuits for providing fuel to the pilot mixer and the main mixer; and, a plurality of valves associated with the fuel nozzle and in flow communication with the feed strip thereof.

Abstract: A method for operating a gas turbine engine including a compressor and a combustor is provided. The method comprises channeling between about 0% to about 8% of the total airflow discharged from a compressor towards a pilot swirler coupled within the burner, wherein the burner includes a main swirler and an annular centerbody extending between the pilot and main swirlers, injecting a portion of the total fuel flow supplied to the burner through a plurality of apertures defined in a hollow pilot centerbody coupled within the pilot swirler, channeling the remaining airflow discharged from the compressor towards the main swirler, and injecting the remaining fuel flow supplied to the burner through at least one main swirler vane coupled within the main swirler, such that the portion of fuel is pre-mixed with a portion of the total airflow.

Abstract: An apparatus for actively controlling fuel flow from a fuel pump to a mixer assembly of a gas turbine engine combustor, where the mixer assembly includes a pilot mixer and a main mixer. The pilot mixer further includes an annular pilot housing having a hollow interior, a primary fuel injector mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing, a plurality of axial swirlers positioned upstream from the primary fuel injector. The fuel flow control apparatus further includes: at least one sensor for detecting dynamic pressure in the combustor; a fuel nozzle; and, a system for controlling fuel flow supplied by the fuel nozzle through the valves. The fuel nozzle includes: a feed strip with a plurality of circuits for providing fuel to the pilot mixer and the main mixer; and, a plurality of valves associated with the fuel nozzle and in flow communication with the feed strip thereof.

Abstract: A mixer assembly for use in a combustion chamber of a gas turbine engine includes a pilot mixer, a main mixer, and a fuel manifold. The pilot mixer includes: an annular pilot housing having a hollow interior, a primary fuel injector mounted in the pilot housing, a plurality of axial swirlers positioned upstream from the primary fuel injector, and a plurality of secondary fuel injection ports for introducing fuel into the hollow interior of the pilot housing. The main mixer includes: a main housing surrounding the pilot housing and defining an annular cavity, a plurality of fuel injection ports, and at least one swirler positioned upstream from the plurality of fuel injection ports. The fuel manifold is in flow communication with the plurality of secondary fuel injection ports in the pilot mixer and the plurality of fuel injection ports in the main mixer.

Abstract: A combustor swirl cup includes coaxial inner and outer swirlers separated by a tubular centerbody. The centerbody includes a bypass inlet surrounding the inner swirler and diverges aft along a perforate inner nozzle to terminate at an annular flameholder. An impingement ring is spaced forward from the flameholder in flow communication with the bypass inlet for receiving cooling air therefrom to impingement cool the flameholder.

Abstract: A mixer assembly for use in a combustor of a gas turbine engine, including a pilot mixer, a main mixer, and a fuel manifold positioned between the pilot mixer and the main mixer. The pilot mixer further includes an annular pilot housing having a hollow interior and a pilot fuel nozzle mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing. The main mixer further includes a main housing surrounding the pilot housing and defining an annular cavity, a plurality of fuel injection ports for introducing fuel into the cavity, and a swirler arrangement including at least three swirlers positioned upstream from the plurality of fuel injection ports, wherein each swirler of the swirler arrangement has a plurality of vanes for swirling air traveling through the respective swirler to mix air and the droplets of fuel dispensed by the fuel injection ports.

Abstract: A swirler arrangement for a mixing assembly of a gas turbine engine combustor, where the swirler arrangement has a centerline axis therethrough, including: a swirler housing including an outer radial wall and an upstream wall; a first plurality of vanes incorporated into the outer radial wall, wherein the first plurality of vanes are oriented at a first angle with respect to an axis through the outer radial wall; and, a second plurality of vanes incorporated into the outer radial wall, wherein the second plurality of vanes are oriented at a second angle with respect to the through the outer radial wall. A first type of passage is defined between adjacent first and second vanes having a first configuration and a second type of passage is defined between adjacent first and second vanes having a second configuration so that air flowing through the swirler arrangement is swirled in a desirable manner.

Abstract: A mixer assembly for use in a combustion chamber of a gas turbine engine including a pilot mixer, a main mixer, and a fuel manifold. The pilot mixer includes: an annular pilot housing having a hollow interior; a primary fuel injector mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing; a plurality of axial swirlers positioned upstream from the primary fuel injector, each of the plurality of swirlers having a plurality of vanes for swirling air traveling through the respective swirler to mix air and the droplets of fuel dispensed by the primary fuel injector; and, a plurality of secondary fuel injection ports for introducing fuel into the hollow interior of the pilot housing.

Abstract: A mixer assembly for use in a combustion chamber of a gas turbine engine includes a pilot mixer, a main mixer, and a fuel manifold positioned between the pilot mixer and main mixer. The pilot mixer includes an annular pilot housing having a hollow interior and a pilot fuel nozzle mounted in the housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing.

Abstract: A method for operating a gas turbine engine including a compressor and a combustor is provided. The method comprises channeling between about 0% to about 8% of the total airflow discharged from a compressor towards a pilot swirler coupled within the burner, wherein the burner includes a main swirler and an annular centerbody extending between the pilot and main swirlers, injecting a portion of the total fuel flow supplied to the burner through a plurality of apertures defined in a hollow pilot centerbody coupled within the pilot swirler, channeling the remaining airflow discharged from the compressor towards the main swirler, and injecting the remaining fuel flow supplied to the burner through at least one main swirler vane coupled within the main swirler, such that the portion of fuel is pre-mixed with a portion of the total airflow.

Abstract: A mixer assembly for use in a combustor of a gas turbine engine, including a pilot mixer, a main mixer, and a fuel manifold positioned between the pilot mixer and the main mixer. The pilot mixer further includes an annular pilot housing having a hollow interior and a pilot fuel nozzle mounted in the pilot housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing. The main mixer further includes a main housing surrounding the pilot housing and defining an annular cavity, a plurality of fuel injection ports for introducing fuel into the cavity, and a swirler arrangement including at least three swirlers positioned upstream from the plurality of fuel injection ports, wherein each swirler of the swirler arrangement has a plurality of vanes for swirling air traveling through the respective swirler to mix air and the droplets of fuel dispensed by the fuel injection ports.

Abstract: A gas turbine engine having a longitudinal centerline axis therethrough, including a fan section at a forward end of the gas turbine engine for producing a first compressed air flow; a first compressor positioned downstream of the fan section and in flow communication with at least a portion of the first compressed air flow, wherein the first compressor produces a second compressed air flow having a designated pressure; a combustor positioned downstream of the first compressor and in flow communication with second compressed air flow, wherein the combustor produces combustion products from a mixture of fuel and air; a first turbine positioned downstream of the combustor and in flow communication with combustion products, wherein the first turbine powers the first compressor by means of a first rotatable drive shaft connected therebetween; and, a second turbine positioned downstream of the first turbine and in flow communication with the combustion products exiting the first turbine, wherein the second turbine

Abstract: A mixer assembly for use in a combustion chamber of a gas turbine engine includes a pilot mixer, a main mixer, and a fuel manifold positioned between the pilot mixer and main mixer. The pilot mixer includes an annular pilot housing having a hollow interior and a pilot fuel nozzle mounted in the housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing.

Abstract: A mixer assembly for use in a combustion chamber of a gas turbine engine includes a pilot mixer, a main mixer, and a fuel manifold positioned between the pilot mixer and main mixer. The pilot mixer includes an annular pilot housing having a hollow interior and a pilot fuel nozzle mounted in the housing and adapted for dispensing droplets of fuel to the hollow interior of the pilot housing.

Abstract: A swirler arrangement for a mixing assembly of a gas turbine engine combustor, where the swirler arrangement has a centerline axis therethrough, including: a swirler housing including an outer radial wall and an upstream wall; a first plurality of vanes incorporated into the outer radial wall, wherein the first plurality of vanes are oriented at a first angle with respect to an axis through the outer radial wall; and, a second plurality of vanes incorporated into the outer radial wall, wherein the second plurality of vanes are oriented at a second angle with respect to the through the outer radial wall. A first type of passage is defined between adjacent first and second vanes having a first configuration and a second type of passage is defined between adjacent first and second vanes having a second configuration so that air flowing through the swirler arrangement is swirled in a desirable manner.

Abstract: The performance of a compression ignition internal combustion engine is improved by optimizing a cylinder pressure-dependent parameter on a full time, full range basis using in-cylinder pressure measurements to determine the actual value of the parameter to be optimized. The basic procedure is to determine the desired or optimum value of the parameter, determine the actual value of the parameter or a related parameter, and then adjusting an engine operating characteristic such as air/fuel ratio to maintain the controlled parameter at its optimum value. The preferred parameter is a cylinder pressure ratio (CPR) obtained by dividing first and second values of cylinder pressure, and sensed at different points in a thermodynamic cycle, by one another. The sensed values are preferably a first value P0, obtained during the compression stroke, and a second value Pa, obtained after combustion is complete.