a ducted fan的用法和样例：
- Some unmanned aerial vehicles can vertically take off and land with the ducted fan system, but there is no valid method to analyze the aerodynamic characteristics of a ducted fan system currently.
- Carrying down or away. Used of a duct or vessel.
- a jet engine that provides extra thrust by means of a ducted fan in its forward end that draws in extra air
- A duct often contains cross braces.
a ducted fan的相关资料：