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WIG-CRAFT
a field for experimenters ?
Why
not ?
A lot of theoretical
research has been done concerning ground effect in relation
to stability and related topics, but very few Wing-In-Ground
effect crafts exist. At the same time, the search for
faster and faster machines has neglected the effect,
sometimes with devastating results. In 2001, Mercedes
built three Le Mans cars. Two of the three cars flipped
over backwards during the race. Almost every year, several
high speed racing catamarans flip. Even small racing
hovercraft at high speed have the tendency to lift at
the front, but this twisting moment can be compensated
by the driver leaning his weight over the front of the
craft. Spectacular crashes from instability need not
be the norm.
Some time ago, a Russian
company built the SERVER, a typical dynamic hovercraft.
This craft traveled (current??) at 120 km/h with only
54 HP. As you see on the image, the propeller and engine
are in front of the craft, pulling the craft instead
of pushing it. This pulling configuration is far more
stable and could be incorporated to create stable WIG
craft designs. Secondly, by installing a folding skirt
in front, the craft could utilize static pressure to
achieve separation from water surface tension, and to
maintain elevation until the craft is traveling fast
enough to maintain support dynamically. The skirt could
be raised and the craft could travel in WIG mode. If
used only on water, a catamaran configuration could
work well. Surface Area, Desired Speed, Cruising Altitude,
Pay Load, Cockpit Size, Horizontal Stabilization, Flaring
Height and even ergonomics, are only some of the factors
that need to be considered for an excellent WIG design.
An other example of original thinking is shown on the
right. The Cushion Crow is a flying body/wing.
Experiments with this
design are very promising. Click on the picture to see
the web page. These are only two examples. There are
many more possibilities. Warning model experimenters:
Due to the behavior of a wing in ground effect, models
can only be used on flat water or the model must
be a large scale.
Most models
are low flying aircraft's !! BUT.........
for a firs dry,
go to this link for an
easy to build paper
model
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