Phil
the nioest wing root I've seen is Ted and Justin's, small radius at the
LE, large at the TE. picture attached. imho this is the way to do it,
the fillet needs to be flexible to allow wing bending without crushing
the fuselage side, so no more than 3 plies of BID at the edge. There are
several Europas with this style but only Ted's has the elegant change of
radius moving aft.
Easier to rig a wing done like this too, something to line up with as it
goes in.
Graham
flyingphil2 wrote:
>
> Hi Fred,
>
> Well my thoughts on this would be as follows:
>
> 1. Is there a problem in that area? Oil flow tests would show up any
> separations
in that area or maybe someone with a dirty aircraft has flown through rain
and has some pictures of the surface flow patterns that were left. If there
is no obvious problem then I'd leave it alone.
>
> 2. If there is a problem then making a really good job of the wing fillets
> would
be the best approach and maybe trying to maximise the radius of that fillet
(larger radius = better). The problem with a large radius is what happens
when you come to the trailing edge of the wing (or in the Europa's case, where
the wing ends and the flap starts). You need to lose that large radius and run
it out to nothing smoothly.
>
> 3. Sealing the wing against the fuselage would definitely be good. On
> gliders,
we use PVC tape but that only works if you have a small 'wing stub' moulded
into the fuselage that the wing butts up to. On a Europa I would say that some
high density foam on the inside of the wing root fillet would do the trick
and when the wings are fitted, the foam is compressed and thus forms a nice
seal.
I.m not sure what gaps people have between the fuselage and the wing fillets
but try and keep them as small as possible.
>
> In terms of drag reduction I would have thought that there is little to do on
the Europa. It's already an excellent design and the use of composite materials
(and ability to build almost any shape) helps this. Compared to some homebuilts
on the market using the same engine, it has to be a very efficient machine.
Having said that, you notice the difference on a glider if the wing roots
are not taped and the controls are not sealed and so all these little bits of
attention to detail would add up and help reduce the drag that little bit
further.
>
> Actually, that's an interesting point above. Out of all the homebuilts
> powered
with a 912S, there can't be many aircraft that are faster than a Europa. There
is the DynAero MCR1 (which I had an amazing flight in once) and that is very
fast but look at the size of it - it's tiny. Anyone have any other comparisons?
>
> Phil
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> Visit - www.EuropaOwners.org
>
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--
Graham Singleton
Tel: +441629820187
Mob: +447739582005
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