On this slide we show a computer drawing of a turbojet engine with an afterburner. Large amounts of surrounding air are continuously brought into the engine through the inlet. We have shown here a tube-shaped inlet like one you would see on an airliner but inlets come in many shapes and sizes depending on the aircraft's mission. At the rear of the inlet, the air enters the compressor. The compressor acts like many rows of propellers with each row producing a small jump in pressure. At the exit of the compressor, the air is at a much higher pressure than free stream. In the burner a small amount of fuel is combined with the air and ignited. Leaving the burner, the hot exhaust is passed through the turbine which extracts energy from the flow of gas to turn the compressor. The afterburner is used to put back some energy by injecting more fuel directly into the hot exhaust. In the drawing you'll notice that the nozzle of the basic turbojet has been extended and there are now a couple of flame holder rings, colored yellow, in the nozzle. When the afterburner is turned on, additional fuel is injected through the hoops and into the hot exhaust stream of the turbojet. The fuel burns and produces additional thrust, but it doesn't burn as efficiently as it does in the combustion section of the turbojet. You get more thrust, but you burn much more fuel. When the afterburner is turned off, the engine performs like a basic turbojet.
Last Updated Thu, May 13 02:38:16 PM EDT 2021
by Tom Benson