Abstract: A method and apparatus to facilitate reducing NOx emissions in turbine engines is provided. The method includes providing an annular shell including a plurality of circumferentially extending panels. The plurality of circumferentially extending panels includes a first panel positioned at an upstream end of the shell and a second panel positioned downstream from, and adjacent to, the first panel. The method also includes forming a plurality of primary dilution holes in the first panel and forming a plurality of secondary dilution holes in the second panel. The dilution holes are configured to discharge dilution air into the shell.

Abstract: A method and apparatus to facilitate reducing NOx emissions in turbine engines is provided. The method includes providing an annular shell including a plurality of circumferentially extending panels. The plurality of circumferentially extending panels includes a first panel positioned at an upstream end of the shell and a second panel positioned downstream from, and adjacent to, the first panel. The method also includes forming a plurality of primary dilution holes in the first panel and forming a plurality of secondary dilution holes in the second panel. The dilution holes are configured to discharge dilution air into the shell.

Abstract: A combustor for a gas turbine engine having a longitudinal axis therethrough, including an outer liner having a forward end and an aft end, an inner liner having a forward end and an aft end, a first dome formed upstream of the outer liner forward end so as to define a first combustion zone radially oriented to the longitudinal axis, and a dome plate having an outer portion connected to an upstream end of the first dome and an inner portion connected to the inner liner forward end, wherein a second combustion zone is defined by the dome plate, the outer liner, and the inner liner substantially perpendicular to the first combustion zone.

Abstract: A gas turbine engine combustor includes outer and inner liners joined together at an annular dome. Outer and inner air swirlers and cooperating fuel injectors are mounted in two rows in the combustor dome. The fuel injectors are joined to a common fuel manifold for simultaneously channeling fuel thereto over an operating range from idle to full power for reducing exhaust emissions.

Abstract: A cyclonic precombustion mixing chamber or prechamber has an axially extending annular cyclonic chamber to vaporize liquid fuel therein and a centerbody centrally disposed within. A fuel injection means introduces liquid fuel radially outward into the cyclonic chamber. The centerbody extends axially through an annular exit of the prechamber to define a throat and throat exit therebetween which is optimally designed for preventing backflash and autoignition. In one embodiment the diameter of the throat is sized to substantially match the diameter of the potential core.

Abstract: The present invention provides a cyclonic precombustion mixing chamber or prechamber having an axially extending annular cyclonic chamber to vaporize liquid fuel therein and a centerbody centrally disposed within. A fuel injection means introduces liquid fuel radially outward into the cyclonic chamber. The centerbody extends axially through an annular exit of the prechamber to define a throat and throat exit therebetween which is optimally designed for preventing backflash and autoignition. In one embodiment the diameter of the throat is sized to substantially match the diameter of the potential core. The diameter of the potential core and the centerbody at the throat exit, D.sub.c, may given by the solution to the following equation;4(D.sub.c /D.sub.t).sup.4 =(.rho./.DELTA.P)V.sub.w.sup.2 (D.sub.w /D.sub.t).sup.2 [1+(D.sub.c /D.sub.t).sup.2 ]where D.sub.t is the diameter of the outer edge of the throat exit, .rho.

Abstract: A gas turbine engine combustor is provided with a combustor dome plate film cooling means having an annular slotted ring to provide a film starting means upstream of a multi-hole film cooled single wall metal dome plate which is annular in shape. One particular embodiment provides a starting slot in the form of a plurality of rings surrounding the edges of the air/fuel nozzle inlet apertures in the dome plate. The cooling holes are disposed in concentric circles about the apertures and angled along radii emanating from the center of the apertures. This produces a cooling film emanating radially from the ring like circular slots around each air/fuel nozzle inlet aperture in the dome plate. Another embodiment provides a starting slot in the form of circumferential rails circumferentially disposed about the inner and outer circumferential edges of dome plate.

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 diluting combustion gases in a gas turbine engine combustor includes injecting primary dilution air into the combustion gases, and injecting trim dilution air into the combustion gases adjacent to the injected primary dilution air. A dilution air injector for practicing the method includes a plate, or centerbody in an exemplary embodiment, having a primary dilution hole for injecting a portion of compressed air into combustion gases as primary dilution air, and a trim dilution hole for injecting a portion of the compressed air into the combustion gases as trim dilution air. The primary and trim dilution holes are sized and configured so that the primary and trim dilution air cooperate with each other for penetrating into and diluting a predetermined portion of the combustion gases.

Abstract: A combustion assembly includes a combustor having inner and outer pilot liners, each being in the form of a lobed mixer having outer and inner cold and hot chutes. A plurality of carburetors are joined to a dome disposed at upstream ends of the liners for providing a pilot fuel/air mixture for generating pilot combustion gases in the hot chutes. A plurality of fuel spraybars are disposed downstream from the carburetors and are aligned radially with the cold chutes for selectively injecting main fuel into main airflow for generating a main fuel/air mixture ignitable by the pilot combustion gases. In a preferred and exemplary embodiment of the invention, lean combustion gases are obtained for reducing NO.sub.x emissions in a relatively short residence time.

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 method of diffusing airflow includes diffusing first and second airflow portions at first and second diffusion rates, respectively, which are unequal for improving pressure recovery. An exemplary diffuser for practicing the invention includes first and second channels separated by a splitter for separately diffusing first and second airflow portions, respectively. The first and second channels have first and second area ratios, respectively, which are unequal for obtaining increased pressure recovery. In the preferred embodiment, the first and second area ratios are preselected for obtaining substantially symmetrical airflow streamlines over a leading edge of the splitter.