Definition
A type of gas turbine engine combustion chamber that combines features of both can-type and annular-type combustors. Several individual cylindrical flame tubes (cans) are arranged in a circle around the engine axis and enclosed within a single common outer casing that forms a continuous ring (annulus). Compressed air from the compressor flows through the shared annular space, while fuel is burned inside each separate can before the hot gases merge and pass to the turbine.
Plain English
An engine burner section that uses several small burner cans grouped in a ring inside one shared outer housing. It is a hybrid of two older designs, giving the steady airflow of a ring-shaped burner with the easier maintenance of separate burner cans.
Context Anchor
Seen in turbine engine systems, especially when comparing different combustion-section designs or reading turbine engine maintenance descriptions.
Derivation
Can' refers to the individual cylindrical flame tubes, which look like metal cans. 'Annular' comes from the Latin 'anulus,' meaning 'ring.' The name describes the layout exactly: cans arranged in a ring.
Why Pilots Care
Combustor design affects how an engine starts, how evenly it burns fuel, and how it behaves at altitude. Pilots flying turbine aircraft may see references to combustor type in engine manuals, and understanding the layout helps when interpreting hot-section inspection findings or troubleshooting uneven exhaust gas temperatures.
Analogy
Picture several small burners spaced around a circle under one shared cover. Each burner is separate, but together they form one ring-shaped burning section.
Intuition Check
“Can” does not mean a storage can here; it means an individual burn chamber. “Annular” does not mean the combustor is one open ring only; in this design, separate cans are arranged in a ring.
Example Sentence 1
The Pratt & Whitney JT3D uses a can-annular combustor, with eight flame tubes arranged inside a single outer case.
Example Sentence 2
Maintenance crews often access the can-annular combustor through inspection panels on the engine casing.