BBerson
Light Plane Philosopher
I am looking for the best way to produce static lift as a means to enhance slow flight.
I have several books about ducted fans. The books all say a ducted fan has more STATIC thrust than the same size unducted prop. The Hiller flying platform Hiller Aviation & Museum | Exhibits is the only example of a ducted fan for static thrust that I know of.
The Hiller platform claims to get 40% of the thrust from the large radius bellmouth intake design and 60% from the props. (see website) The large intake is good for static lift but would add much drag in the case of normal high speed propulsion. I only want static lift.
Is the Hiller claim likely to be correct? And why?
P.S I found some past comments by searching this forum, from orion, about the definition of ducted fans and shrouded props. ( a duct length less than half the prop diameter would be called a shroud) So the Hiller platform is a shrouded prop by that definition.
BB
Edit: I found this interesting paper that seems to apply to my question:http://4wings.com.phtemp.com/lib/files/Raspet_c.pdf
I have several books about ducted fans. The books all say a ducted fan has more STATIC thrust than the same size unducted prop. The Hiller flying platform Hiller Aviation & Museum | Exhibits is the only example of a ducted fan for static thrust that I know of.
The Hiller platform claims to get 40% of the thrust from the large radius bellmouth intake design and 60% from the props. (see website) The large intake is good for static lift but would add much drag in the case of normal high speed propulsion. I only want static lift.
Is the Hiller claim likely to be correct? And why?
P.S I found some past comments by searching this forum, from orion, about the definition of ducted fans and shrouded props. ( a duct length less than half the prop diameter would be called a shroud) So the Hiller platform is a shrouded prop by that definition.
BB
Edit: I found this interesting paper that seems to apply to my question:http://4wings.com.phtemp.com/lib/files/Raspet_c.pdf
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