Not all airplanes are powered by one or more jet engines. While jet engines are undoubtedly common, some airplanes are powered by a turboprop engine. Turboprop engines are used in propeller airplanes. Airplanes with one or more propellers are manufactured with a special type of engine that drives their respective propeller or propellers. Known as a turboprop engine, it consists of five main parts.
#1) Air Intake
All turboprop engines have an air intake. As the name suggests, this part is designed to transfer air into the engine. Turboprop engines still rely on combustion — just like jet engines — so they require the use of an air intake. The air intake will transfer air into a turboprop engine where it’s mixed with fuel.
#2) Speed Reduction Gearbox
The speed reduction gearbox is a type of transmission system used in turboprop engines. It’s used to lower the engine’s revolutions per minute (RPM). Turboprop engines turn propellers by outputting RPM. The higher the RPM output, the faster the propellers will turn. If the RPM is too high, though, airplanes may consume an excessive amount of fuel. A speed reduction gearbox improves fuel efficiency by keeping the RPM output in check.
Also known as the combustion chamber, the combustor is the space within a turboprop engine where combustion takes place. Combustion is an explosive reaction that occurs when fuel and air are mixed together and ignited. It’s the primary force behind which turboprop and jet engines function. In turboprop engines, air and fuel are mixed together inside of the combustor. Once ignited, combustion occurs within the combustor that drives the propellers.
Another important part of a turboprop engine is the turbine. The turbine is a rotary device that’s connected to the propellers. As a turboprop engine generates combustion and RPM output, it will turn the turbine. The turbine will then turn the propeller to which it’s connected.
#5) Propelling Nozzle
Finally, turboprop engines have a propelling nozzle. The propelling nozzle is a device that’s designed to increase propulsion in turboprop engines. It compresses the combustion gases produced within the combustor before exhausting them. By exhausting compressed gases, airplanes receive a small but noticeable increase in propulsion.
Turboprop engines typically contain five parts: an air intake, a speed reduction gearbox, a combustor, a turbine and a propelling nozzle. With these five parts, they are able to turn the propellers on an airplane.