Precompressor Cooling With Water and Oxidizer for Small Access to Space Vehicles

The development of a pre-compressor mass injection system for extending the flight Mach number and altitude of conventional military afterburning turbofan engines is proposed. The injection of water and liquid oxidizer such as liquid oxygen can be used toenhance the performance of these engines so that they may power the reusable air-breathing first stage of a space access vehicle. The fluid injected into the inlet may serve three purposes. First, it can cool the air entering the compressor so that theengine may be operated to higher flight Mach number. Second, it can increase the net mass flow through the inlet so that the engine can generate morethrust. Third, it can provide additional oxidizer so that additional fuel can be added in the engine afterburner further augmenting the engine thrust. It is anticipated that the coolant injected upstream of the compressor may be vaporized before enteringthe compressor face. This minimizes the effect of the coolant injection system on the engine operation thereby simplifying the development effort. This system development includes the development of water/oxidizer supply system, the spray injection system,modification or extension of engine controls and potentially the modification of the afterburner and nozzle. An accelerator afterburning turbojet engine that is capable of flight to high Mach number and high altitude has significant commercial and militarymarkets in space launch applications. This technology can also be applied to high-speed, long-range, rapid response missiles. Supersonic business jets also have the need to accelerate quickly to their cruise altitude and speed. This technology could enablethe engines of these vehicles to be optimized for cruise, while still have the capability to climb and accelerate with the assistance of this technology. Water injection can be optimized to increase the output power of industrial gas turbines for electricpower generation.