A Brayton cycle engine including an inner wall assembly defining a detonation combustion region upstream thereof extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath. A method for operating the engine includes flowing an oxidizer through the gas flowpath; capturing a portion of the flow of oxidizer via the inner wall; flowing a first flow of fuel to the captured flow of oxidizer; producing a rotating detonation gases via a mixture of the first flow of fuel and the captured flow of oxidizer; flowing at least a portion of the detonation gases downstream to mix with the flow of oxidizer; flowing a second flow of fuel to the mixture of detonation gases and oxidizer; and burning the mixture of the second flow of fuel and the detonation gases/oxidizer mixture.

A scramjet engine has a first passage forming member and a second passage forming member. A passage is formed between a first surface and a second surface. The passage has an upstream zone, a combustion zone and a downstream zone. A cavity of a concave shape is provided on the first surface in the combustion zone. The first passage forming member has a convex section located in the upstream zone, a first fuel injection section configured to inject fuel into the passage from a first fuel nozzle provided for the convex section, and a second fuel injection section configured to inject fuel to the cavity. The second passage forming member has a third fuel injection section configured to inject fuel to a direction toward the first surface from the second surface in the passage through a second fuel nozzle provided in the downstream zone.

A Brayton cycle engine including an inner wall assembly defining a detonation combustion region upstream thereof extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath. A method for operating the engine includes flowing an oxidizer through the gas flowpath; capturing a portion of the flow of oxidizer via the inner wall; flowing a first flow of fuel to the captured flow of oxidizer; producing a rotating detonation gases via a mixture of the first flow of fuel and the captured flow of oxidizer; flowing at least a portion of the detonation gases downstream to mix with the flow of oxidizer; flowing a second flow of fuel to the mixture of detonation gases and oxidizer; and burning the mixture of the second flow of fuel and the detonation gases/oxidizer mixture.

A ram-air duct system includes a ram-air duct configured to receive a flow of ram-air from a ram-air inlet and discharge the flow to a ram-air outlet. The system also includes a heat exchanger configured to exchange heat with air within the ram-air duct, an auxiliary air passageway and an electrically-driven air mover configured to move a flow of auxiliary air along the auxiliary air passageway for discharge into the ram-air duct through an intermediate inlet between the ram-air inlet and the ram-air outlet. The air duct system further includes a controller configured to selectively operate the ram-air duct system in an auxiliary supply mode in which the air mover and/or a control valve are controlled to cause the flow of auxiliary air to be discharged into the duct through the intermediate inlet, to thereby control a rate of heat exchange between the heat exchanger and air within the duct.

A ramjet including: a combustion area having an air inlet and an exhaust outlet; and a fuel cell in fluid communication with the air inlet and a fuel supply of the ramjet, wherein the fuel cell is in thermal communication with the combustion area.

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.

A turboramjet has a housing with an intake and an exhaust. The housing houses a heat exchanger, a turbojet section and a ramjet section downstream of the turbojet section. The heat exchanger has an air path and a coolant path. The air path is configured to receive air from the air intake. The heat exchanger has a first section made from a first material and a second section made from a second material, the second material having a lower melting point and a lower density relative to the first material. A bypass air passage selectively bypasses the turbojet section to supply air to the ramjet section, and the coolant path uses fuel as a coolant and is configured to supply the fuel to the turbojet section.

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 an inner wall assembly defining a detonation combustion region upstream thereof extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath. A method for operating the engine includes flowing an oxidizer through the gas flowpath; capturing a portion of the flow of oxidizer via the inner wall; flowing a first flow of fuel to the captured flow of oxidizer; producing a rotating detonation gases via a mixture of the first flow of fuel and the captured flow of oxidizer; flowing at least a portion of the detonation gases downstream to mix with the flow of oxidizer; flowing a second flow of fuel to the mixture of detonation gases and oxidizer; and burning the mixture of the second flow of fuel and the detonation gases/oxidizer mixture.

Provided herein is a fuel injector capable of providing fuel into a jet engine operating at hypersonic speeds. Embodiments may include a system for fuel injection for an engine traveling at supersonic speeds. The system may include a fuel injection strut extending between opposing walls of an inlet to the engine, and a porous surface extending across at least a portion of the fuel injection strut. The fuel may be introduced into the inlet of the engine through the porous surface of the fuel injection strut. The porous surface of the fuel injection strut may extend along a fuel injecting portion of the fuel injection strut spaced a predefined distance from the opposing walls of the inlet. The porous portion of the fuel injection strut may include a porosity of about 100 pores per square inch or lower porosities as dictated by the specific design considerations.