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Old Oct 14, 2014, 03:59 AM
Hamburger
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Quote:
Originally Posted by FiftySlicks View Post
...was a joy to fly. Well, not so much on the road below, which was perfect except for the camber, which kept sucking it towards the sides.
You could always add a 10$ heading hold gyro like the helicopter guys used.
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Old Oct 21, 2014, 11:02 PM
Who, ME?
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Euclid Ohio
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Ekrano...cycle?

http://www.gizmag.com/go/6864/
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Old Oct 30, 2014, 07:57 AM
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Quote:
Originally Posted by nickchud View Post
If you scroll around amongst the pictures on this thread, you'll see loads of possibilities.
Here's a really simple starting point. and this guy did a really good experiment

good luck
Nick

Thanks for posting that important test.

As a 17000 hr airline transport pilot I would not want to be flying anything with a tendency to pitch up into a stall or flip with no room to recover! That's suicidal.

In this video
WSH 500 Discovery Channel (6 min 49 sec)
, that's the Korean WHS 500 WIG, the most developed WIG in recent time, at 4:38 in the clip the commentator says 'if it flies too high it may flip'. Not good.

It is true it may be controlled by electronics, but interestingly when investigating that the air France that crashed off Brazil by being stalled from 35000 ft right into the ocean, it was found that the aircraft was designed with less than the required static margin and that the electronics artificially provided the required static margin for certification. It was argued that if it had the required static margin it may have recovered even if the pilots mishandled it.

From this standpoint the Bixel comes first!

Regards to all, keep up the good work,

Armour.
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Old Oct 30, 2014, 11:54 AM
What could possibly go wrong?
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Market Harborough
Joined Apr 2006
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A bit like this from 1964..
Donald Campbell Killed in Water Speed Record Attempt (3 min 11 sec)
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Old Nov 03, 2014, 04:09 PM
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Euclid Ohio
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Interesting WIG layout:

Hovering WIG (Wing In Ground-effect) Vehicle - 2013 Project Compilation (5 min 49 sec)
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Old Nov 30, 2014, 01:52 PM
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Hello!

I have been watching this thread for a while now and wanted to get some feedback on our own WIG vehicle. I am part of a team of student engineers whom have to build a ground effect vehicle. The wings of the WIG are made from 1 piece carbon fiber, while the rear is made from 3MM MDF. Tomorrow it will have its maiden flight with an onboard camera so we can see the wheels lift off the ground.


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Old Nov 30, 2014, 02:54 PM
flying since 2000
Winterthur ZH, Switzerland
Joined Mar 2009
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Looking good! Goodluck with the maiden, please tell us how it went!
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Old Dec 01, 2014, 12:15 AM
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Looks good. What kind of forebody do you plan? It may need to be quite long to get the balance right. May I suggest to balance it for flight and then move the CG back if u must. Ask nick about flying the Flightship! If it sticks to the ground and doesn't want to lift off try increasing the wing incidence before moving the cg back. An aft CG is very very difficult to control!
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Old Dec 01, 2014, 07:00 PM
AnhedralFSWGEV -- with canards
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Ireland, Cork, Model Farm Road
Joined Mar 2013
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Show me your bottom...

The view from the top looks fancy (although not too new, it's very Lippisch-style), however, I have the feeling that the underside is at least as important as the front and the top for a GEV (because of the GE)... Would you please put a picture showing the underside of your baby and explain how you designed it in regards of driving the airflow?

My design (in very early stages) will probably greatly take advantage of your explanations... Thank you in advance :-)
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Old Dec 02, 2014, 07:02 AM
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Our vehicle definately has some lift, but not much. As you can see in the video the front of the vehicle is lifted about 1cm above the ground, while the rear wheel stays in touch. You can also hear the front start to scrape when we release throttle, which indicates the front doesnt touch "in flight". I personally wouldn't really consider it a GEV yet. What do you think ?
The "body" of the craft which houses the battery and electronics is a 3D printed box suspended at the bottom of the wings (not shown in picture). Here is a picture of the underside:

Homemade lippisch ground effect vehicle (0 min 47 sec)



We are currently thinking about positioning the EDF in front of the wings so it partially blows underneath them, which should increase ground effect. We also wanted to place the balsa "supports" on top of the carbon fiber wings so they dont block the airflow as much as they do now. The current model was sacrificed in testing as you can see in the video

The first test runs were made with the elevators pointing down as far as they could, so the front was being pushed down. The test where the GEV suddenly rises and flies off were made with the elevators in a horizontal position. So If we continue with this model we have to find the "sweet spot" for the elevators angle.
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Old Dec 10, 2014, 01:31 AM
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Hi snikkeldak
I think that craft is very close to achieving ground effect. Maybe a higher angle of attack on the h- stab
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Old Dec 13, 2014, 10:02 AM
AnhedralFSWGEV -- with canards
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Ireland, Cork, Model Farm Road
Joined Mar 2013
7 Posts
I think the perpendicular underside beams are not the greatest thing, you want to keep fluid dynamics as much as possible and use the flow to lift longitudinally (like the upper inside side of a tube or a cone) instead of breaking against your 2 walls and losing (wasting) energy.
On the top side, I'd say, smooth your camber to give more grip to the Bernouilli. Angular breaks are just gonna give you cavitation (lower lift), even at low speeds.
Also, you really want to measure your air speed at all times. In near-ground flight, these tails are tricky with acceleration and the plane tends to go head over heels when you accelerate too quickly (you saw it...) because the tail becomes suddenly very heavy (that's what it's designed for) ant the front suddenly gets a lot of lift (same...). You might want to get rid of the tail and control a moving mass inside the body of your plane so your CoG is always moving to counter the lift/push according to your altitude. And you then may want to reduce/get rid of the tail and the induced drag/turbulences.
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Old Dec 14, 2014, 12:53 PM
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"The first test runs were made with the elevators pointing down as far as they could, so the front was being pushed down. The test where the GEV suddenly rises and flies off were made with the elevators in a horizontal position. So If we continue with this model we have to find the "sweet spot" for the elevators angle."

What u describe here is a crash anytime you leave GE.
The wing must have greater incidence or AoA than the tail to be stable. -2 deg is a good starting point.
By extending the fuselage forward of the wing(forebody) you can move the batteries or ballast forward to bring the CG to about 20% MAC.
To find MAC measure midway from tip to root and draw a line from LE to TE, measure the distance where that line goes through LE to TE and count 20% back from the LE.
If she doesn't want to lift off, increase the nose up attitude to get a higher AOA .
Wish u success.
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