Understanding the Gas Turbine Engine Combustion Section

For a majority of aircraft to achieve and sustain heavier-than-air-flight, they rely on the constant combustion of fuel and air mixtures. With gas turbine engines, this process is carried out within the combustion section. To efficiently carry out combustion and optimally fly, the combustion chambers ensure proper fuel and air mixing, efficient burning, optimal cooling to avoid damages, and the delivery of exhaust gases to the turbine section of the engine.

Generally, the combustion chamber of a gas turbine engine is located between the compressor and turbine section, allowing for air to be thoroughly compressed before ignition and for exhaust gases to be directly supplied to the turbine. To ensure optimal flow and functionality, the combustion chambers are always oriented coaxially with the compressor and turbine sections. Depending on the aircraft and its particular needs, combustion chambers may either be can type, can-annular type, or annular type.

Can type combustion chambers are most often found on turboshaft engines and APUs, and they typically feature an outer casing and an inner liner or chamber liner that is constructed from perforated stainless steel. As gas turbine engines that utilize can type combustion chambers often have multiple units, each can must be connected together to ensure that combustion is spread throughout the assembly. With components known as flame tubes, a spark can be made in two of the lower chambers, and then flames can spread throughout tubing to each can until all are ignited. Depending on the engine type, flame tubes may come in various forms.

With the can-annular type combustion chamber, combustion zones are separated with individual liners and fuel injector components similar to the can type combustor. Despite this, the can-annular type differs in the fact that there is a shared ring casing to hold each combustion zone. As such, liner holes, flame tubes, and other components ensure that air flows circumferentially so that ignition is easier. Due to the construction of the assembly, the can-annular type is also capable of exhibiting a uniform temperature profile for its exit flow which benefits the turbine section. While can-annular types are fairly efficient for a number of applications, they may require more maintenance as compared to a can combustor.

The final type is the annular combustor, and they prove to be the most widely used type for aircraft engines. Devoid of separate combustion zones, the annular combustor features a ring casing and continuous liner. With their construction, less surface area and a lighter assembly is provided, though combustion is quite uniform. Additionally, annular types exhibit the lowest pressure drop values of the three combustors and are simplistic in design. Altogether, the advantages that annular type engines provide make them very desirable for many modern aircraft.

Regardless of which of the three combustor types is present within a gas turbine engine, all three follow the same basic principles and operations. During a typical flight operation, air is drawn into the compressor to increase pressure, and then it is provided to the combustion chamber at a high velocity. Through the use of nozzles, fuel injector components, and a fuel manifold, fuel and air can be efficiently mixed together and then ignited within the combustion chamber. As a result of ignition, fuel and air mixtures explode into rapidly expanding, hot exhaust gases that push into the turbine inlet of the engine. As exhaust gases are forced against the rotor blades of the turbine assembly, the mechanical motion of the blades can be harnessed to power and drive various sections of the engine and aircraft. As such, the gas turbine engine can become fairly self-sufficient once it begins the combustion process.

Through the combustion chambers of a gas turbine engine, the aircraft can efficiently mix and ignite fuel and air for propulsion generation. When you are in need of parts for engine manufacturing, repair, or replacement, look no further than Internet of Components. As a leading online distributor of aviation parts, we are your sourcing solution for fuel system components and other aviation items that have been sourced from top global manufacturers. Explore our expansive database today, and you may begin the purchasing process at any time through the submission of an Instant RFQ form. Get started now and experience how Internet of Components is revolutionizing the part procurement process.