What Is the Difference Between a Turboprop and Turbofan?

Both turboprop engines and turbofan engines are turbine engines that thermodynamically operate the same, producing thrust for flight. The two engines function in slightly different ways and use unique processes to make use of exhaust, and to produce thrust. Both types offer benefits for different operations, so it is helpful to understand what defines each. Depending on your specific aircraft, either a turboprop or a turbofan could be a better option for purchase, so this blog will explore the ins and outs of each type.

A major distinguishing factor is how both engines handle exhaust, as each engine produces thrust from a different path of airflow. In a turboprop engine, exhaust from the combustion process is used to power a propeller. This propeller produces thrust for the engine and leaves no exhaust energy to be expelled. On the other hand, the exhaust from both combusted and non-combusted air in a turbofan engine is released directly from the rear to produce thrust. The different designs for producing thrust also lead to different factors that determine efficiency.

While both engines function well in flight, and while there is no superior option, a few limiting design factors should be considered prior to purchase. First, since turboprop engines rely on propellers, different blade sizes and speeds produce different levels of power. Due to the need to increase blade lengths for greater speeds, efficient speed operating ranges are generally limited. Turboprop engines therefore operate best at subsonic speeds. Alternatively, turbofan engines can operate at higher speeds by controlling and lowering the speed of intake air as it passes through compressors at the front. Some of this air is further compressed while some of it is directed straight to the jet engine. This path prevents turbofan engines from being limited by high airspeeds the way that a turboprop engine is.

Meanwhile, turboprop engines face unique limitations that are not present in turbofan engines, including the engine’s internal temperatures, the compression ratio, and the nozzle design. While the engine takes in a lot of air, the nozzle can only produce a certain amount of thrust. Although they consume more fuel and are less efficient than turboprop engines, turbofans produce more relative thrust and have overall better performance capabilities. For example, the fastest plane to ever fly relied on a turbofan engine and reached an altitude over 85,000 feet.

While turboprop and turbofan engines function differently, they are both safe and reliable options for your aircraft for different reasons. A turboprop’s propellers are the main safety hazard with their design as the blades move quickly and can cause harm to anyone nearby. Additionally, the propeller needs adequate clearance from any part of the plane that could lead to aerodynamic issues. The design of turbofans allows them to be mounted in close quarters without the issue of aerodynamics as the propeller is not a concern. While turboprop engines produce vibrations, they also are less prone to heating, and are safe and reliable for purchase.

If you are in the market for a cost-efficient engine for aircraft flying at subsonic speeds, a turboprop engine will offer the most for your money. At the same time, if you are operating at speeds faster than that of sound, a turbofan engine will prove more efficient. Whatever your needs, you can rely on ASAP Fasteners for premium and reliable hardware and aerospace parts. Owned and operated by ASAP Semiconductor, quality is the cornerstone of our business, and we operate under AS9120B, ISO 9001:2015, and FAA AC 00-56B accreditation, alongside a No China sourcing policy. Additionally, we have a team of experts working around the clock 24/7x365 who can answer any questions via phone or email. If you have a specific part in mind to purchase, allow us to become your parts procurement partner and get started by filling out and submitting a Request for Quote form. Within 15 minutes, you can expect to receive a custom, competitive quote on any item!