Turbine engines are excellent for creating high-power thrust with very little added weight. A turbine engine operates by compressing air, mixing it with fuel, igniting the mixture and directing the exhaust gases. Of course the process is more involved than that, but those are the basics. Turbine engines weigh less, and have a much higher power-to-weight ratio, but they are expensive to build and maintain because of the high pressures and temperatures contained within.
In a gas turbine engine, air is drawn in through the front of the engine by the compressor fans. The compression chamber is shaped like a cone, so as the air is forced into the smaller space, it is compressed, often by a factor as high as 30 times the original pressure. The compressor fans direct the compressed air into the combustion area, where fuel is mixed into the highly compressed air. Multiple fuel injectors spray a stream of fuel into the combustion chamber, where it mixes with the heavily compressed air. The air and fuel mixture is ignited in the combustion chamber, and the resulting explosion shock wave and rapid expansion move rearward into the turbine itself. The fan vanes of the turbine are attached directly to the output shaft, which acts as the drive shaft. The fan vanes of the turbine catch the rapidly expanding gases and turn rapidly, turning the output shaft along with them. In some engines the fan vanes turn a drive shaft, but in some airplane engines, such as turboprops, the output shaft is used to turn the propeller blades in order to provide propulsion for the aircraft.
Unfortunately, the turbine blades can only translate a portion of the expanding gases into rotational energy. The energy that the fan blades can't translate into power must be directed away from the engine so no damage in caused. The exhaust ports are always to the rear of the turbine blade assembly so that any excess kinetic energy can be directed away from the delicate engine parts.
