A scramjet engine has first and second passage forming members. A passage is formed between the first surface and the 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 which injects the fuel into the passage from a fuel nozzle provided for the convex section, and a second fuel injection section which injects the fuel to the cavity. The second passage forming member has a third fuel injection section which injects the fuel to a direction toward the first surface from the second surface in the passage through the second fuel nozzle provided in the downstream zone.

A system for bistatic radar target detection employs an unmanned aerial vehicle (UAV) having a ramjet providing supersonic cruise of the UAV. Deployable antenna arms support a passive radar receiver for bistatic reception of reflected radar pulses. The UAV operates with a UAV flight profile in airspace beyond a radar range limit. The deployable antenna arms have a first retracted position for supersonic cruise and are adapted for deployment to a second extended position acting as an airbrake and providing boresight alignment of the radar receiver. A mothership aircraft has a radar transmitter for transmitting radar pulses and operates with an aircraft flight profile outside the radar range limit. A communications data link operably interconnects the UAV and the tactical mothership aircraft, transmitting data produced by the bistatic reception of reflected radar pulses in the UAV radar antenna to the mothership aircraft.

Provided are systems and methods for a hydrogen-fueled supersonic turbojet engine system comprising: an inlet; combustor; fuel storage; high-pressure turbine and low-pressure turbine wherein the initial pressure of the high-pressure turbine is greater than the initial-pressure of the low-pressure turbine; a compressor operably attached to the low-pressure turbine; and a plurality of stream lines configured to circulate cryogenic liquid molecular hydrogen fuel through a plurality of heat exchangers positioned in the airframe and a precooler in the engine, wherein the plurality of fuel stream lines connects the fuel storage to the low-pressure and high-pressure turbines and the combustor.

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 Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. A strut is extended through the gas flowpath between the longitudinal walls. An inner wall assembly is extended from the longitudinal wall and the strut into the gas flowpath. The inner wall assembly and strut together define a plurality of detonation combustion regions 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.

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.

Provided is a wind tunnel system capable of supporting high velocity applications and methods for constructing the same. Some aspects include a sub-surface storage space for storing large volumes of air for one or more of extended testing times, large test sections, and supersonic airspeeds. Some aspects include test sections sized for use with full scale sections of aircraft or major aircraft parts. Some embodiments store air at a constant volume and some sore at a constant pressure. Some embodiments include the use of cavities that appear as a result of industrial or geologic processes, including salt domes and abscesses remaining after carbon extraction.

Light weight fan blades for turbofan jet engines are disclosed. The fan blades may be fabricated from an aluminum alloy. To enhance the hardness of the leading edge of the fan blade, a titanium sheath may be attached to the leading edges of the fan blades. To prevent galvanic coupling between the titanium and the aluminum, a polymeric liner may be disposed between the protective titanium sheath and the aluminum fan blade. The liner may be fabricated from a polymer material, such as a polyimide or another high performance polymer.

A system for bistatic radar target detection employs an unmanned aerial vehicle (UAV) having a ramjet providing supersonic cruise of the UAV. Deployable antenna arms support a passive radar receiver for bistatic reception of reflected radar pulses. The UAV operates with a UAV flight profile in airspace beyond a radar range limit. The deployable antenna arms have a first retracted position for supersonic cruise and are adapted for deployment to a second extended position acting as an airbrake and providing boresight alignment of the radar receiver. A mothership aircraft has a radar transmitter for transmitting radar pulses and operates with an aircraft flight profile outside the radar range limit. A communications data link operably interconnects the UAV and the tactical mothership aircraft, transmitting data produced by the bistatic reception of reflected radar pulses in the UAV radar antenna to the mothership aircraft.