An Overview of How Jet Engines Work

Powered flight has significantly evolved over the decades, changing how we define global transportation and military defense. The driving force behind many modern aircraft are jet engines, complex machines that convert fuel into thrust capable of driving aircraft forward and airborne. In this blog, we will cover the essential structures composing jet engines, focusing on how they achieve combustion and generate the thrust necessary to sustain flight. 

The intake is responsible for directing ambient air into the engine, where it is then compressed by a series of rotating blades to dramatically increase air pressure and temperature, setting the stage for effective combustion. Following this, the compressed air enters the combustion chamber, where fuel is introduced and ignited. The resulting high-temperature, high-pressure gases pass through a turbine, which extracts energy to drive the engine’s compressor and any auxiliary systems. Finally, the remaining gases exit the engine through the nozzle, creating thrust.

While this basic configuration is common across most designs, there are several different variants of jet engines used today. These include turbojets, turbofans, turboprops, and turboshafts, each suiting specific aircraft and performance requirements with slightly different operating mechanisms.

The Fuel Combustion Process 

As we briefly discussed, combustion within a jet engine takes place in a carefully engineered chamber where compressed air, delivered from the compressor stage, mixes with finely atomized fuel—usually aviation kerosene such as Jet-A or JP-8. This precise air-fuel mixture is then ignited by igniter plugs, initiating a rapid increase in gas temperature and velocity. 

Achieving optimal combustion is a complex balancing act between improving fuel efficiency while maintaining safety and minimizing harmful emissions. Moreover, as temperatures inside the combustion chamber often exceed 3,000°F (approximately 1,650°C), advanced materials are needed to withstand extreme heat and thermal cycling without degrading, the standard choice being ceramic-coated titanium alloys. 

Jet engine subtypes like turbojets and turbofans share this core combustion principle, but they often have variations in their combustion chambers to bolster performance for their specific operational needs. For example, high-bypass turbofan engines used in commercial aviation often employ annular combustion chambers—a circular, ring-shaped design that surrounds the engine core. This configuration promotes more uniform heat distribution and efficient airflow, which helps reduce emissions and stabilize combusionstion. 

Furthermore, to have precise control over combustion, many modern jet engines employ advanced fuel management systems, including Full Authority Digital Engine Control (FADEC). These sophisticated digital controllers continuously adjust fuel flow and combustion parameters in real time, helping engines adapt to flight conditions. The result is better fuel economy, enhanced reliability, and lower environmental impact, all while maintaining the powerful thrust that jet engines are known for. 

How Thrust is Sustained Across Jet Engine Types

Thrust in a jet engine is primarily generated by the rearward expulsion of high-velocity gases, but the mechanism by which it is accomplished and sustained varies slightly depending on engine type. In turbojet engines, nearly all of the thrust comes from the exhaust gases produced by combusted fuel passing through the turbine and out the nozzle. These engines rely solely on accelerating hot gases to generate forward momentum, which makes them effective at high speeds. 

By contrast, turbofan engines divert a significant portion of the incoming air around the engine core via a large front-mounted fan. This bypassed air does not enter the combustion chamber and instead flows through a separate duct, mixing with the core’s exhaust gases at the rear to produce thrust. The ratio of air bypassing the core compared to the air passing through it is known as the bypass ratio, a parameter that affects fuel efficiency, noise levels, and overall engine performance. 

Engines with low bypass ratios, such as some military aircraft turbofans, balance thrust production between the fan and core exhaust, optimizing for high-speed performance and responsiveness. High-bypass turbofan engines, which are dominant in commercial aviation, feature a large volume of bypass air to maximize fuel usage, lessen noise output, and support sustained subsonic flight, making them ideal for passenger aircraft. 

Meanwhile, to uphold steady thrust throughout all phases of flight, jet engines often rely on a range of components that are adjusted by the FADEC system to further improve internal airflow and engine performance. For instance, adjustable stator vanes in the compressor section help control the angle of incoming air, reducing the risk of compressor stall during rapid throttle changes or at varying altitudes. Similarly, variable-area exhaust nozzles can expand or contract to manage the pressure and velocity of exhaust gases, ensuring efficient thrust output as conditions shift. 

Source Reliable Jet Engine Components from ASAP Integrated Distribution 

From compressor blades to FADEC systems, each part of a jet engine must be manufactured and sourced to exacting standards to avoid significant operational and safety consequences. For this reason, having a dependable procurement partner is essential. ASAP Semiconductor, through its platform ASAP Integrated Distribution, serves as a one-stop resource for those seeking top-quality jet engine components and thousands of other products that meet stringent industry requirements. 

Every item offered through ASAP Integrated Distribution is from a trusted entity, ensuring traceability, documentation, and performance integrity. Moreover, our customers will always benefit from competitive pricing and timely delivery, as well as solutions tailored to their unique needs. Taking all of this into account, peruse our inventory and get in touch with a team member to see how we can serve your operations.