The Turboprop engine, commonly known as Turboprop, is one of the most emblematic engines in the aerospace industry. It is a reference and will remain so in the aviation of tomorrow.
Whether in the military with the A400-M or in the civilian with the Beechcraft Starship 2000A or in the first aid aircraft like the Breguet 1100 Atlantic. Turboprop is used throughout aviation with very different performances from one another.
Breguet 1100 Atlantic
We present here how this engine works with explanations of the different parts belonging to the propulsion system, passing by a few words of history about its origins.
If we were to summarize briefly how the Turboprop works, we could say that it is the engine’s gas turbine, providing the power needed for the propulsion system that will allow the rotation of a multi-pole propeller.
Military aircraft A400-M
Let’s go back in time with a brief contextualization of the creation of this propeller engine. In 1926, the Royal Aircraft Establishment explored the concept of a turbine that would rotate a central shaft and then a propeller.
It took another three years to get the first patenting of the turboprop engines by György Jendrassik, a Hungarian mechanical engineer. Despite some combustion problems but also with the war the project of a possible engine is abandoned.
It was not until 1942 that we saw the appearance of the first turbo-propelled engine, this time designed by a German engineer Max Adolf Muelle.
Simulation air flow
Operation Turbo propeller
The operation of the turboprop engine is based on the same principle as the turbofan the jet engine principle.
The only difference with the turbo fan is that in the case of the Turboprop, the jet engine drives a propeller and not a fan. For the operation of the jet engine, first of all, the air at room temperature is driven by the propeller, which forces some of it into the compressor.
The role of the compressor is, as its name suggests, to compress the air in order to give it the optimum conditions (pressure & temperature) for combustion with fuel.
Once the air is conditioned and ready for combustion, it enters the combustion chamber where the energy is created by mixing air/fuel that ignites.
This energy drives a turbine that is connected to a reducer (a chain of gears allowing two rotating parts to have a different rotation speed) that makes the propeller rotate: This is a cycle that, once started, will not stop as long as there is fuel in the tanks.
The A400-M picture : Meredith Plessis
Article written by Couranjou Pierre and Jules Jilcot