A fuel nozzle for a combustor may include a primary fuel passage having a primary fuel outlet. A secondary fuel passage having a secondary fuel outlet. A valve located within the secondary fuel passage. The valve may include a stationary hub having a plurality of first angled surfaces. The valve may include a movable sleeve having a plurality of second angled surfaces. Each of the plurality of first angled surfaces aligns axially with a respective one of the plurality of second angled surfaces to define a slot therebetween. The valve is movable between a plurality of positions to open, to close, or to partially open the slots.

A computer-implemented method for multi-mode operation of a combustion system, a combustion system, and a heat engine are provided. The method includes initializing combustion of a fuel/oxidizer mixture, determining whether conditions at the combustion system meet or exceed a first threshold operating parameter, transitioning to detonation combustion of the fuel/oxidizer mixture if conditions at the combustion system meet or exceed the first threshold operating parameter, and maintaining or increasing fuel flow through a deflagrative fuel circuit if conditions at the combustion system do not meet or exceed the first threshold operating parameter.

Provided is a gas turbine combustor that can achieve improvement of the combustion stability. A gas turbine combustor includes a pilot burner of the diffusion combustion type, a pilot flow control valve that regulates a flow rate of fuel to be supplied to the pilot burner, a main burner of the premix combustion type arranged on an outer circumference side of the pilot burner, main flow control valves that regulate flow rates of fuel to be individually supplied to burner sectors into which the main burner is sectioned in a circumferential direction, and a controller configured to control the pilot flow control valve and the main flow control valves. The controller controls the main flow control valves such that, when fuel is to be supplied to all the burner sectors, a difference in fuel flow rate occurs between at least one burner sector and the other burner sectors among the burner sectors.

A Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. An inner wall assembly is extended from the longitudinal wall into the gas flowpath. The inner wall assembly defines a detonation combustion region in the gas flowpath upstream of the inner wall assembly.

A Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. An inner wall assembly is extended from the longitudinal wall into the gas flowpath. The inner wall assembly defines a detonation combustion region in the gas flowpath upstream of the inner wall assembly.

Combustor systems are provided. For example, a combustor system comprises a combustor having forward and aft ends and including annular inner and outer liners that each extend generally along an axial direction and define a combustion chamber therebetween. The combustor system also comprises a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle and including a pilot swirler. The outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle and extending about the outlet. A total combustor airflow through the combustor comprises a pilot swirler airflow that is greater than about 14% of the total combustor airflow and a main mixer airflow that is less than about 50% of the total combustor airflow.

A mixing assembly for a combustor includes: a pilot mixer including a pilot housing extending along a mixer centerline and a pilot fuel nozzle; a main mixer surrounding the pilot mixer; a fuel manifold between the pilot and main mixers; a mixer foot extending from a main housing of the main mixer; a main swirler body surrounding the main housing defining a mixing channel between the main housing and the main swirler body; and a main fuel ring in the mixing channel connected to the main housing by main fuel vanes, at least one of the main fuel ring and main fuel vanes including fuel injection ports for discharging fuel into the mixing channel, wherein the fuel injection ports are disposed non-uniformly relative to the mixer centerline, so as to produce a static pressure difference therebetween in response to mixer air flow passing around the main fuel ring.

A method of reducing noise from a combustor of a gas turbine engine includes the steps of establishing a maximum noise limit that may be for a particular frequency range. A primary fuel flow percentage, which may be emitted from a fuel nozzle arrangement having various groupings of simplex and duplex nozzles, is then established. An immersion depth measured between an aft rim of a swirler and a distal tip of the fuel nozzles may then be reduced thereby reducing the noise amplitude.

A Brayton cycle engine and method for operation. The engine includes an inner wall assembly and an upstream wall assembly each extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath between the inner wall assembly and the upstream wall assembly. The engine flows an oxidizer through the gas flowpath and the inner wall captures a portion of the oxidizer. The engine further adjusts the captured flow of oxidizer via the upstream wall and flows a first flow of fuel to the captured flow of oxidizer to produce rotating detonation gases. The engine flows the detonation gases downstream and to mix with the flow of oxidizer, and flows and burns a second flow of fuel to the detonation gases/oxidizer mixture to produce thrust.

Fuel distribution manifolds and combustors are provided. A fuel distribution manifold includes a main body and a fuel circuit that is defined within the main body. The fuel circuit includes an inlet section extending generally axially from an inlet to a first branch section and a second branch section. The first branch section and the second branch section diverge circumferentially away from each other as they extend axially from the inlet section to a respective first outlet and a respective second outlet.