Wing in ground effect boat

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captarmour

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Joined
Feb 9, 2013
Messages
368
Location
Roseau, Dominica.
very interesting info here, especially from orion. i understand he is no longer with us.

i have tried a few models and hope to build a manned craft one day. what i am attempting is to have the cp move back as the craft climbs out of GE increasing stability and causing a descent. my most successfull model would fly hands off IGE and needed almost full up trim OGE.

IMHO that is the only way to make safe wig. i do not use the reverse delta.

any news on the korean hoverwing?
 

Titanium UK

New Member
Joined
Jun 16, 2013
Messages
1
Location
Eastbourne, East Sussex, England, UK
Good Day
We are currently developing a WIG based on an inflatable boat.(personal use only for crossing the English channel between France And England....ferry costs are astronomical and wife gets sea sick!!!! )
The inflatable has 6 individual tubes for sea worthiness and all the safety equipment to Solas and Maritime And Coastguard Agency standards....
The wing is canvas laid between an aluminium leading and trailing edge(not dissimilar to universal's flying hovercraft) with plates/keels at each end. These plates are very thin and strong and drop down into the water approx 1m depth BSL thus giving optimum air flow under the wing to assist lift at lower speeds.
The boat is a 4.5 m inflatable with aluminium floor and an inflatable keel beneath the floor... so very light.
We have installed 2 small slapper plates some 3.5 m off of the rear of the vessel via structural aluminium tube so as the angle of attack of the craft increases when in flight the slapper plates impact the water surface and lowers nose....eventually meeting a happy medium where the plate effortlessly skims the surface.
As there is 2 slapper plates some 2 m apart this adds further stability keeping wings level.
The vessel is currently powered by 50hp outboard with extra long shaft mounted very low to the water surface to make sure the prop is submerged as long as possible at approx 800mm beneath the hull. Therefore she can fly at 600-700mm above ASL
This engine runs this vessel at 45 knots so should get her airbourne!
If the prop comes out of the water thrust reduces and the vessel settles back down...and the slapper plate also assists.
Trials to take place over the summer.
We believe this will work and provide a vessel that is comfortable and quick to travel the open ocean.
Thank you
 

N15KS

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Joined
Jan 2, 2004
Messages
139
Location
Chicago
As described, it looks like the rear slapper plates will have the opposite effect. If your craft gets too low, they will rotate the wing, to a lower angle of attack; causing it to descend further. This would be negative stability.

I built several WIG vehicles, with forward "feelers", to provide stability. Being forward, the normal force from the feelers, reacts the negative pitching moment of the wing. As the vehicle ascends, the wing rotates to a lower angle of attack. As it descends, it rotates to a higher angle of attack. This is positive stability.

Do you have any sketches of your slapper plate design?

SB-3A.jpg
 

captarmour

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Joined
Feb 9, 2013
Messages
368
Location
Roseau, Dominica.
It is nice to see WIG is being given attention. IMHO for any flying machine to be safe, it must be balanced for flight in the event a gust or unforeseen event causes it to lift OGE. My tests with rc models show a tendency for straight winged low aspect ratio to not want to lift off unless the CG is moved back and then when airborne becomes uncontrollable.
 

Sockmonkey

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Apr 24, 2014
Messages
1,823
Location
Flint, Mi, USA
Honestly the biggest issue with WIGE craft is the fact that it has the same awkward configuration constraints as a seaplane.
The prop has to be high enough to be clear of waves and splash, but it also has to be low enough not to put the thrust-line too high above the fuselage. It travels over rough water great, but first you have to take off from that same rough water.
Honestly I think the best thing would be if it had those spring-ski things Rutan's seaplane does.
 

nucleus

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Joined
Mar 21, 2016
Messages
65
Location
Atlanta, Georgia
Wing in Ground Effect Boat - Not Enough Wing!

I like the idea of ski-like things that Rutan uses, but it should probably be centered to prevent excess yaw moment when you dig one into a wave.

When I see people's WIG designs the main mistake that I see is not enough wing area!

I think designers are too in love with speed relative to airplanes, but that speed is a killer when you try to take off and land. One, you can't can't get going fast enough to take off. Two, the impact on the waves when you land.

I think we need to aim for far lower stall speeds, like 30 MPH.

Yes, that big wing makes for a slower craft, but it is still faster and more fuel efficient than a boat, and your chances of being able to handle rough water are much improved.
 

Sockmonkey

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Joined
Apr 24, 2014
Messages
1,823
Location
Flint, Mi, USA
I think Starman might be best off with a configuration like this.

The stub fins on the outdrive unit will do the same job as the tail, only reacting faster because of the higher density of water.
Using a water drive unit will give more "oomph" for the initial acceleration. Fewer fiddly bits overall.
The top speed will be less due to water drag on the prop, but the lack of hull drag makes it easy to cruise at racing-boat speeds.
 
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