RamJamJet – A RamJamJet is an advanced Ramjet design incorporating new technologies that allows for efficient, high thrust output at much lower speeds than standard ramjets.
Turboramjet – The air turborocket is a form of combined-cycle jet engine. The basic layout includes a gas generator, which produces high pressure gas, that drives a turbine/compressor assembly which compresses atmospheric air into a combustion chamber. This mixture is then combusted before leaving the device through a nozzle and creating thrust.
Scramjet – A scramjet (supersonic combustion ramjet) is a variant of a ramjetairbreathing jet engine in which combustion takes place in supersonicairflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion (hence ramjet), but whereas a ramjet decelerates the air to subsonic velocities before combustion, the airflow in a scramjet is supersonic throughout the entire engine.
Propfan – A propfan, also called an open rotor engine, or unducted fan, is a type of aircraft engine related in concept to both the turboprop and turbofan, but distinct from both. The design is intended to offer the speed and performance of a turbofan, with the fuel economy of a turboprop. A propfan is typically designed with a large number of short, highly twisted blades, similar to a turbofan’s bypass compressor (the fan itself). For this reason, the propfan has been variously described as an “unducted fan” or an “ultra-high-bypass (UHB) turbofan.”
Turboprop – A turboprop engine is a turbine engine that drives an aircraft propeller. In its simplest form a turboprop consists of an intake, compressor, combustor, turbine, and a propelling nozzle.[2] Air is drawn into the intake and compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts. The hot combustion gases expand through the turbine. Some of the power generated by the turbine is used to drive the compressor. Thrust is obtained by the combusting gases, pushing toward a (vectored) surface in front of the expanding gas.
Turboshaft – A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust and convert it into output shaft power. They are even more similar to turboprops, with only minor differences, and a single engine is often sold in both forms.
Pulsejet – A pulsejet engine (or pulse jet) is a type of jet engine in which combustion occurs in pulses. A pulsejet engine can be made with few[1] or no moving parts,[ and is capable of running statically (i.e. it does not need to have air forced into its inlet typically by forward motion).
