Most Advanced eVTOL Propulsion System: Adaptive Ducted Fan

[edwest4]

View: https://www.youtube.com/watch?v=orLjrswcpxI

 

[AeroFranz]

Cool, but It's not like no one's ever thought of varying the geometry of ducted fans. We'll see if the complexity buys its way onto a vehicle.
On a separate note, there's no eVTOL that can be certified with only four lift posts. It's not controllable in one engine out conditions.

 

[Zoo Tycoon]

A similar solution to this was used on the Harrier. In it’s early version an inflatable duct extension, known as the “Elephant ear” was tried. This is the black (rubber) edge around the air intake lip on the P1127 below.


However the final form was a series of simple spring loaded, differential pressure operated blow in doors just behind the intake lip. These produced the same effect but without the complexity of sensing, control and actuation.

Elegant design is where more is provided with less.

Gee those Harrier guys were good.

 

[yasotay]

A similar solution to this was used on the Harrier. In it’s early version an inflatable duct extension, known as the “Elephant ear” was tried. However the final form was a series of simple spring loaded, differential pressure operated blow in doors just behind the intake lip. These produced the same effect but without the complexity of sensing, control and actuation.

Elegant design is where more is provided with less.

Gee those Harrier guys were good.

@Zoo Tycoon - I had always wondered at the reason for those doors on the intake. Thanks for another question answered.