Ekranoplan?

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Charles
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Ekranoplan?

Post by Charles » Fri Oct 17, 2008 12:54 pm

Hey all,

Ekranoplan? You hear me say, and I can hear you too with WTF?
Here checkout the link below and see what you think to a model pulse-jet version?

http://news.bbc.co.uk/1/hi/magazine/7638659.stm
http://news.bbc.co.uk/1/hi/magazine/7635441.stm

All the best,
Charlie

Bruno Ogorelec
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Re: Ekranoplan?

Post by Bruno Ogorelec » Tue Dec 30, 2008 6:15 pm

Charlie, you can play with a WIG vehicle on your own on a much smaller scale, as one is commercially available in the US:

http://www.hovercraft.com/content/index ... Path=34_53

I have little doubt that it could be pulsejet-powered, but it would be noisy as hell. It would be a fantastic thing for the Burning man, though.

larry cottrill
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Re: Ekranoplan?

Post by larry cottrill » Tue Dec 30, 2008 6:36 pm

Bruno -

Man, what's astounding is how little wing area it takes to do this! Of course, I realize this must be pretty lightweight construction.

Yes, with a decent pulsejet that would be a real blast! It would get you banned everywhere. Ha.

L Cottrill

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Re: Ekranoplan?

Post by Bruno Ogorelec » Tue Dec 30, 2008 10:08 pm

Larry, the point is that the ground effect acts as if it extended the wingspan. So, imagine the wingspan tripled and you get to somewhere near the equivalent of the 'normal' aircraft.

Another way to do it is to create an air 'cushion' under the vehicle by pushing air under the vehicle. Imagine a brick-shaped box without the front and bottom sides. Like an inverted straight-sided shovel.

Put an aircraft engine and propeller on the leading edge of the box. The prop will pull the vehicle forward and push air underneath until it lifts on the air 'cushion'. At speed, mere forward movement pushes enough air underneath to keep the vehicle in the air. (Of course, it pays to have the 'box' profiled in a more aerodynamic way, but the essence is there in my description.

I can easily imagine a valveless pulsejet blowing underneath such a craft. Bet that a lot of noise would be muffled by such an engine position.

larry cottrill
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Re: Ekranoplan?

Post by larry cottrill » Wed Dec 31, 2008 1:48 pm

Bruno -

Seems like a good use for a compact "linear" engine like the old linear FWEs. Mount the engine backward so the intake points aft. Pick up all the exhaust pipe effluent with a "scoop" that bends it around underneath the wing-shaped body, with a low-speed "bird wing" type airfoil (what I mean is, a lot of camber to the bottom surface).

I have a weird little old book about an invention called the "dynamator". Basically, a jet or rocket blast is turned downward by a small set of Venetian blind style vanes that are controllable over a reasonable range of angles, so you can choose how to proportion rearward vs downward thrust. The book is from somewhere around 1950. I'd scan some of it to post if I had a way to do it, because some of the design ideas are fairly interesting.

L Cottrill

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Re: Ekranoplan?

Post by Bruno Ogorelec » Wed Dec 31, 2008 2:21 pm

larry cottrill wrote:Seems like a good use for a compact "linear" engine like the old linear FWEs. Mount the engine backward so the intake points aft. Pick up all the exhaust pipe effluent with a "scoop" that bends it around underneath the wing-shaped body
I don't think I understand the layout you are proposing.

I see promise for the under-body engine because it will be contained within the scoop, muffling some of the noise. Pulsejets don't mind foreign-body ingestion, so dust and debris is not a problem.

larry cottrill
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Re: Ekranoplan?

Post by larry cottrill » Fri Jan 02, 2009 5:05 pm

Bruno -

The "scoop" is rear-facing, with the (normally speaking) tail end of the engine spouting into it. This bends around the wing leading edge like a big "recuperator" so that the exhaust (along with lots of entrained air) flow directly onto the bottom wing surface. The negative curvature of this surface turns the air (both from the "recuperator" and from forward motion) downward to form the cushion.

An admitted defect in this scheme is that the rearward facing inlet would need to be carefully designed to minimize its spoiler effect on the normal top-surface air flow during forward motion.

L Cottrill

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Re: Ekranoplan?

Post by Bruno Ogorelec » Fri Jan 02, 2009 8:09 pm

larry cottrill wrote:Bruno -

The "scoop" is rear-facing
Hmmm... but then, it wouldn't generate the same aerodynamic effect, would it? It would be a wing, not a scoop.

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