Endothermic fuel compositions comprising 50% or more by volume decahydronaphthalene, including cis-decahydronaphthalene, trans-decahydronaphthalene or a mixture thereof, for use as endothermic fuels in hypersonic vehicles and particularly for use in dual-mode ramjet or supersonic combustion ramjet air breathing engines. Methods for operating a ramjet or scram jet engine wherein the endothermic fuel is used for cooling the combustor and for combustion in the combustor.

Endothermic fuel compositions comprising 50% or more by volume decahydronaphthalene, including cis-decahydronaphthalene, trans-decahydronaphthalene or a mixture thereof, for use as endothermic fuels in hypersonic vehicles and particularly for use in dual-mode ramjet or supersonic combustion ramjet air breathing engines. Methods for operating a ramjet or scram jet engine wherein the endothermic fuel is used for cooling the combustor and for combustion in the combustor.

A scramjet engine includes first and second flow path forming members and first and second fuel injection devices. A flow path formed between the first and second flow path forming members includes a turbulence forming region where compressed air is introduced and a combustion region located downstream thereof. The second flow path forming member is formed with a protrusion in the turbulence formation region. The first fuel injection device is configured to inject fuel into the compressed air via a first fuel nozzle. The second flow path forming member is formed with a cavity located in the combustion region. The second fuel injection device is configured to inject fuel into the compressed air via a second fuel nozzle. The cavity is provided with an inclined surface connected to a bottom surface. An inclination of the inclined surface is adjusted so that a shock wave is generated in the combustion region.

A scramjet engine includes first and second flow path forming members and first and second fuel injection devices. A flow path formed between the first and second flow path forming members includes a turbulence forming region where compressed air is introduced and a combustion region located downstream thereof. The second flow path forming member is formed with a protrusion in the turbulence formation region. The first fuel injection device is configured to inject fuel into the compressed air via a first fuel nozzle. The second flow path forming member is formed with a cavity located in the combustion region. The second fuel injection device is configured to inject fuel into the compressed air via a second fuel nozzle. The cavity is provided with an inclined surface connected to a bottom surface. An inclination of the inclined surface is adjusted so that a shock wave is generated in the combustion region.

Vehicles, such as aircraft, may include turbine-based combined cycle power plants (TBCC) for power to achieve high-mach speeds. An anti-unstart configuration provides control for transitioning between the amount of air directed to either engine during operation of gas turbine engine and scramjet engines, to avoid unstart during operation above sonic speeds.

Vehicles, such as aircraft, may include turbine-based combined cycle power plants (TBCC) for power to achieve high-mach speeds. An anti-unstart configuration provides control for transitioning between the amount of air directed to either engine during operation of gas turbine engine and scramjet engines, to avoid unstart during operation above sonic speeds.

A motor and fuel-powered hybrid system of a rocket thruster is disclosed, which mainly provides power through a motor and a fluid fuel injector. In particular, at the beginning stage of the rocket lift-off, the motor drives the compressor to provide power to send the rocket into air. When the speed and height of the rocket gradually increase, the fuel is ignited to give power to keep propelling the rocket, thereby reducing the fluid fuel that needs to be carried on the rocket, increasing the rocket's loading space and enhancing the carrying capacity.

A motor and fuel-powered hybrid system of a rocket thruster is disclosed, which mainly provides power through a motor and a fluid fuel injector. In particular, at the beginning stage of the rocket lift-off, the motor drives the compressor to provide power to send the rocket into air. When the speed and height of the rocket gradually increase, the fuel is ignited to give power to keep propelling the rocket, thereby reducing the fluid fuel that needs to be carried on the rocket, increasing the rocket's loading space and enhancing the carrying capacity.

A motor and fuel-powered hybrid system of a rocket thruster is disclosed, which mainly provides power through a motor and a fluid fuel injector. In particular, at the beginning stage of the rocket lift-off, the motor drives the compressor to provide power to send the rocket into air. When the speed and height of the rocket gradually increase, the fuel is ignited to give power to keep propelling the rocket, thereby reducing the fluid fuel that needs to be carried on the rocket, increasing the rocket's loading space and enhancing the carrying capacity.

Airframe integrated scramjet engines are disclosed. Scramjet engines within the scope of this disclosure may be configured to integrate smoothly with an airframe of a hypersonic flight aircraft or vehicle. The scramjet engine may include capture shape of an inlet configured to capture airflow, a combustor configured for combustion of fuel and air, and an exit shape of a nozzle configured for expansion of the combusted fuel and air to provide hypersonic thrust. In some embodiments, the scramjet engine has a fixed geometry and a transitioning cross-sectional shape over its full length. The scramjet engine is configured to be a component of launch vehicle system.