Definition
A propulsion arrangement in which a multi-bladed fan is enclosed within a cylindrical duct or shroud, used in turbofan engines to accelerate a large mass of air rearward to produce thrust. The duct shapes and contains the airflow around the fan, improving efficiency and reducing tip losses compared with an unshrouded propeller.
Plain English
A fan that sits inside a tube or housing. The tube guides the air the fan pushes back, making it more efficient than a fan or propeller spinning out in the open.
Context Anchor
Seen in jet engine basics, especially when comparing turbofan engines with other jet engine types.
Derivation
Ducted comes from duct, from the Latin ductus meaning a channel or pipe for guiding flow. Calling the fan ducted simply means it is enclosed in a channel that directs the air it moves.
Why Pilots Care
A ducted fan improves thrust efficiency, reduces noise, and allows higher bypass ratios compared with an open propeller or pure turbojet.
Intuition Check
Do not think of a ducted fan as just a cabin cooling fan. In this context, the fan and its surrounding duct are part of the engine system that moves air rearward to help produce thrust.
Example Sentence 1
The ducted fan at the front of a turbofan engine produces most of the engine's thrust.
Example Sentence 2
During preflight, the mechanic inspected the ducted fan blades for damage before engine start.