Contraction of air stream from propellers; (a) free fan (b) ducted fan | Download Scientific Diagram
![The ideal shape for a multirotor 'ducted-fan' that can dramatically improve thrust and flight time. | Capolight Electronics Projects. The ideal shape for a multirotor 'ducted-fan' that can dramatically improve thrust and flight time. | Capolight Electronics Projects.](https://capolight.files.wordpress.com/2015/01/contra-rotating.jpg)
The ideal shape for a multirotor 'ducted-fan' that can dramatically improve thrust and flight time. | Capolight Electronics Projects.
![Schematic and instrumentation of the 559 mm diameter ducted fan system | Download Scientific Diagram Schematic and instrumentation of the 559 mm diameter ducted fan system | Download Scientific Diagram](https://www.researchgate.net/profile/Cengiz-Camci/publication/267503059/figure/fig1/AS:392070436016142@1470488284573/Schematic-and-instrumentation-of-the-559-mm-diameter-ducted-fan-system_Q640.jpg)
Schematic and instrumentation of the 559 mm diameter ducted fan system | Download Scientific Diagram
![Streamlines at the inlet and exit of a ducted fan for a) hover and b)... | Download Scientific Diagram Streamlines at the inlet and exit of a ducted fan for a) hover and b)... | Download Scientific Diagram](https://www.researchgate.net/profile/Cengiz-Camci/publication/269784918/figure/fig2/AS:669007262806019@1536515169098/Streamlines-at-the-inlet-and-exit-of-a-ducted-fan-for-a-hover-and-b-edgewise-flight.jpg)
Streamlines at the inlet and exit of a ducted fan for a) hover and b)... | Download Scientific Diagram
![engine - At what point is a turbine powered ducted propeller considered a turbofan? - Aviation Stack Exchange engine - At what point is a turbine powered ducted propeller considered a turbofan? - Aviation Stack Exchange](https://i.stack.imgur.com/O37qN.jpg)