What Is a Combustor? Definition, Meaning and Concept
A combustion chamber is a component in which air and fuel mix, ignite, and burn, and is found in certain types of engines. Various types of engines use combustion chambers, and they can take various basic forms of design. Jet engines, turbines, and special classes of engines called ramjets and scramjets use a combustion chamber as part of their design. They can fit into one of three general design types, but they all operate on the same principles.
All gas turbines, or jet engines, have a combustion chamber where fuel mixes with air and burns. The component is analogous to a cylinder in a typical automobile engine. Jet engines use a compressor to inject air into the combustion chamber, where it mixes with vaporized jet fuel and ignites. Burning jet fuel creates hot gases that then spin the turbine. The turbine projects these exhaust gases at the rear of the engine, through a nozzle, creating thrust.
A typical combustion chamber can be one of three basic types of design. All combustion chamber assemblies tend to be circular in shape, but can be distinguished by the specific configuration of the burner chambers. A can combustion chamber consists of several independent burner chambers, each resembling a can, with its own distinct housing, fuel injection, and ignition components, arranged together in a ring.
Annular or "cannular" combustion chambers are similar to can combustion chambers in that they consist of a series of smaller can-shaped burner chambers arranged in a ring. The difference is that the ring itself acts as a common housing for all burner chambers, although each chamber will have its own separate ignition and fuel supply systems.
An annular combustion chamber is also ring-shaped, but the burner itself is a large ring-shaped chamber. These types of combustion chambers have many advantages over the other two basic types, including greater simplicity, which reduces maintenance and improves efficiency. The injection and ignition assemblies are simpler, the ignition and combustion processes are more uniform, and other aspects of technical performance tend to outperform the other types as well. For this reason, most modern jet engines tend to use this type of combustion chamber, and most efforts to improve this engine component focus on this type of combustion chamber.