Thanks for your useful reply
> >I have some questions, but before anyone gets ideas.....
> >2) Can anyone describe the plan shapes of common foils like Peels
> > Sky Tigers, Paua's etc?
> > Specifically, is the leading and trailing edge curve
> > mirrored around the centre line or not?
> > How much of the leading/trailing edge is 'straight' before it
> > curves to the tip profile?
> The Tiger is rectangular, I believe.
> The Peel and, I presume, the Paua pretend to be Elliptical, but in fact the
> middle few (5?) cells are identical. For convenience, I assume - they are
> so similar to start with that any difference required to make a perfect
> ellipse is lost in the underflow.
If they are elliptical, then that means the curvature is symmetric about
the centreline. This means that the centre of pull you talk about below
curves back from the centre of the kite.
My currently-being-contructed kite is made of 2 ellipses, one for the
front edge and one for the rear, with a straight line running through
the point 30% back from the leading edge of the centre rib (widest point
in a clark-y rib profile, except I'm not using the clark-y directly, I
modified it a bit just for fun, and I've left off the tips to have a
reasonably sized final rib profile)
Therefore, I think the centre of pull is also in a straight line?
Whatever, the design makes sense to me in a gut feel kind of way.
> On the Chevron, the only the middle 4 cells aren't tapered. The front and
> rear taper is identical.
I thought so from your fotos. One of my designs-to-be-built I admit is
similar, but with no parallel centre section, and different front and
> From a design point of view, you can do whatever you like :-)
> If you draw a line from the line throught the primary bridle tow-point and
> continue it to the skin, you mark the point of the effective point of pull
> on canopy. You might like to arrange for these points to form a straight
> line across your kite. This is what the Sputnik-4 achieves.
> I actually curve this line int eh Chevron (it curves forward in the middle
> of the kite) and I *think* that this helps to counter tip-drag induced
> bananaing, but this is unproven.
Well, that's a thought. I am toying with going the other way, ie
having the tips forward of the centre, as in some more modern fighter
and light aircraft wing designs.
The bridle may become more interesting though (BTW I notice the Chevron
bridle becoming more complicated as time passes, I also notice you are
using some bridle features from the N-Gen....)
I'm also toying with various ideas for reducing the number of bridle
lines in a cross bridle (and still have it fly decently), but it's
probably all been done before.....
I'm also reinforcing every rib so I can switch between bridling every
2nd or every 3rd rib.....
And yes, this is more about building things than enything else, it
doesn't really matter if one of my kites isn't the next buggy engine of
note, I'm having fun, and I can't afford 'real kites' anyway, building
is much cheaper for me (and I spent most of the weekend waiting for the
wife to finish with the sewing machine....)
And another thing, has anybody ever bridled a foil with dihedral like an
airplane wing, ie the centre closer to you than the tips? If not why
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