TDI turbojet engines provide a smooth and completely variable thrust output in response to vehicle specific commands. The engine control responds to the flight system and controls the engine thrust output by regulating the speed of the engine between idle and the maximum shaft speed.
Low Cost/Compact Configuration
TDI engines were designed for expendable vehicle applications using high production turbocharger rotating components, design simplicity, and ease of manufacture. These engines have radial compressors, radial turbine wheels, and annular combustors mounted between the compressor and turbine wheels allowing for a short compact configuration.
The rotating components for TDI engines are of a low inertia design for ease of engine cranking. The engines then provide assistance in cranking by igniting the combustor early in the starting sequence. This unique feature allows TDI engines to be "windmill" started, or a small gas generator cartridge can be utilized for a rapid start sequence.
The continuous combustion system of TDI engines permit the use of a wide variety of low and high volatility fuels. In addition, TDI engines have the unique feature of providing pre-warmed fuel to a rotary atomizer which provides ultra-fine fuel droplets for easy starting, rapid burning, and complete combustion.
No Lubricating Oil Required
The metered fuel is directed into the rear of the engines for cooling the internal engine components and lubricating the bearings. The precision fuel transport system assures the proper cooling and lubrication of the engine's internal components with the secondary benefit of pre-warming the fuel just prior to entering the combustion chamber. Since no lubricating oil is required, there will be additional capacity for onboard fuel resulting in increased vehicle range.
The exteriors of TDI engines are cooled by air routed through the engine isolating external components from high temperature exposure. Therefore, conventional, low cost materials are utilized for these external components, with the additional benefit of reduced infrared (IR) signature.
Full Authority Engine Control Law
The engine control law performs all of the engine management functions such as starting, accelerating, steady state governing, self testing, and shut-down operations. The control system also interfaces with air data sensors to compensate for changes in air density at the engine intake conditions. Logic can be incorporated into the vehicle flight computer.
A generator with a small rotor that is directly coupled to the engine shaft provides vehicle electrical power for the complete duration of a mission. This same rotor can also provide an electrical start and then automatically transfer into the generator mode.