Abstract: A combustor for rich-quench-lean combustion includes a combustor shell, a combustion chamber delimited by the combustor shell, and fuel injectors. The combustion chamber includes a primary zone, a quench zone, a secondary zone, and an outlet arranged in axial flow series. Openings through the combustor in the quench zone provide a quench air flow into the quench zone. A method for rich-quench-lean combustion for the combustor includes contemporaneously injecting a rich air-fuel mixture into the primary zone and injecting a second air flow into the quench zone in which the second air flow is equal to or less than four times the primary air flow.

Abstract: A component of a gas turbine engine includes a cooling passage extending through a wall from a first surface to a second surface bounding a primary flow of the gas turbine engine. The cooling passage includes a metering section and a diffuser section. The metering section extends from an inlet towards an outlet along a centerline. The diffuser section extends from the metering section to the outlet. The diffuser section includes a fore wall and a back wall opposite and downstream from the fore wall relative to a primary flow direction of the primary flow. The fore wall and the back wall define a plurality of cross-sections normal to the centerline. Each cross-section includes a semi-elliptical portion formed by the fore wall and a semi-rectangular portion formed by the back wall.