Types of Turbine Engines

As the most widely implemented engine type for modern aircraft, the gas turbine is a type of continuous and internal combustion engine. While sharing some similar components, there are a few primary types of turbine engines that are commonly used, each offering unique characteristics and advantages that may benefit varying aircraft models. Turbojets, turboprops, turbofans, and turboshafts are all propulsion systems that cater to varying needs of aircraft and aviation, each serving as one of the most common forms of turbine engines.

As one of the earliest turbine engine types, the turbojet engine comprises a compressor, combustion chamber, turbine section, and exhaust. With the use of an air inlet, ram air can be fed into the compressor at rapid speeds to be mixed with fuel. Once the mixture is ready, an igniter within the combustion chamber will begin the combustion process. As the rapidly expanding exhaust gases force their way from the combustion chamber, they will cause turbine blades to revolve as they pass through. By driving the turbine of the turbojet engine, the entire propulsion system can sustain its operation with ease. Once the gases have finally passed through the turbine section, they are expelled from the system through a nozzle to achieve more propulsion.

As a turbine engine produced before World War II, the turbojet engine serves as the simplest type of the family. Even with their relatively small size, the turbojet engine is capable of reaching very high speeds. Nevertheless, it has high fuel consumption, runs loud, and is often held back in range and endurance. As such, the turbojet engine is not often used for many airliners, rather being reserved for various military models.

During the 1940s, the turboprop engine came about as the next member of the turbine engine family. First implemented on an aircraft in 1945, the turboprop engine consists of a gas turbine engine, reduction gear box, and a propeller. As compared to other types of gas turbine engines, the turboprop is fairly similar in its operation. Their major difference, however, is that they utilize harnessed energy from combustion in order to drive a propeller assembly. To achieve this, energy from exhaust gas is transferred through a shaft and gear train so that the blades may be operated.

Reduction gearing is critical to the operation of a turboprop engine, due to the fact that the optimal performance of the propellers is often reached at speeds much slower than the standard operating values of the engine. As such, the turboprop engine excels the most when traveling between 250 and 400 mph, as well as between 18,000 and 30,000 feet. Furthermore, the speed at which turboprop engines can travel nestles them between conventional piston powered aircraft and the turbojet engine in their performance.

As the turboprop engine is fairly similar in its construction to other types, it does not take long to become familiar with them if one is comfortable with other turbine engines. As compared to the other members of the turbine engine family, the turboprop is quite fuel efficient and excels in a standard set of speeds and altitudes. Despite this, the turboprop engine is fairly limited in its forward airspeed and the gearing system present in the assembly can be heavy and requires more maintenance to avoid failures.

As a combination of turbojet and turboprop features, the turbofan engine serves as the most widely used type for passenger airliners. With large duct fans placed at the front of the engine assembly, a great amount of air can be funneled into the compressor for use. Additionally, a secondary air stream diverts air around the combustion chamber, allowing for increased propulsion. Turbofan engines may be either low bypass or high bypass, determined by the amount of air that is diverted from the engine core. For aircraft that are high-speed military models, low-bypass turbofan engines may be used and extra thrust can be achieved through the implementation of augmenters or afterburners.

Due to the design of the turbofan engine and its characteristics, operations can be quieter than turbojets and optimal fuel consumption may be achieved at standard speed ranges. As a compromise between high speeds and high altitudes, the turbofan engine is often implemented on many air transport aircraft. Despite their advantages, such turbine engines are heavier than turbojets, and they are less efficient at very high altitudes.

As the fourth major type of turbine engine, the turboshaft utilizes a power shaft to drive assemblies that are not propellers. As compared to other types such as the turbojet engine, the turboshaft engine is not used to produce thrust. Instead, the engine is most often implemented in order to drive a turbine, such as on a helicopter. For larger aircraft, turboshafts have also been used as an auxiliary power unit (APU).

Depending on the need of the aircraft or helicopter, turboshaft engines may be produced in a variety of styles, shapes, and speed ranges in order to accommodate specific applications. As compared to similar engines such as the piston engine, turboshaft engines are much smaller and can achieve higher power-to-weight ratios during their operation. Despite this, they can be quite loud during flight and their gear systems will require regular maintenance to protect their integrity.

With the various turbine engines available, a number of aircraft can achieve heavier-than-air flight with ease. As a premier purchasing platform for aviation needs, Aerospace Sphere is your sourcing solution for all of the aircraft turbine engine parts that you have been searching for. We invite you to explore our expansive part catalogs where you can find a plethora of new, used, and obsolete items that we have sourced from top global manufacturers. To ensure that you only receive the best, each and every item has been rigorously tested and inspected for quality assurance. If you would like to receive a competitive quote on parts that you are interested in, fill out and submit an Instant RFQ form as provided on our website. Once received, a dedicated account manager will reach out to you in 15 minutes or less.