Variations on Arup planform?

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cluttonfred

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Over the years I have seen some studies on the Zimmerman planform used on the Vought V-173, the reverse Zimmerman that almost makes a rounded delta wing, squares and circles.
6AB4538F-DCB2-4A5E-9A1B-7712974A9683.png
On the other hand, I have not seen any formal analysis of straight-leading edge planform used so successfully on the Arups and related designs.
4237D489-5771-4E3B-B17D-70934617E864.jpeg
I’m especially curious to find out if anyone has experimented with a simplified, straight-line version of the Arup (like an octagon with three sides cut off) which would be much easier to build and integrate control surfaces.
PNG image.png
Anyone have any leads?
 
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rotax618

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You can see from the remains of this Arup S2 that the wing was essentially a rectangular wing with circular tips and control surfaces, these could be shaped from foam, using modern materials.1B2BC7A2-9B34-41EF-AA15-886DADB43319.jpeg
 

TFF

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Someone with lots of interest should visit and start the camera. Before it is covered up.
 

WINGITIS

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Ok I have had a look at the Spitfire planform, semi elliptical....it has the true mathematical ellipse overlaid over a wing drawing, they are slightly different.

Then using "MS paint I have modified the original ratio which if we say is 1:1 to 2, 2.5 and a 3:1 ratio of that to get 3 different shapes to consider...

Not a straight leading edge but definitely some ARUP style possibilities.

You could vary the ratio to suit what you want or just vary the back half ratio etc etc..

Then if you look at the lift distribution you can get an idea of what will be best for your requirements.

Cheers
spitfire-ellipse and pure elipsoid overlay COMBINED.jpgspitfire-ellipse and pure elipsoid overlay COMBINED 2 to 1.jpgspitfire-ellipse and pure elipsoid overlay COMBINED 2.5 to 1.jpgspitfire-ellipse and pure elipsoid overlay COMBINED 3 to 1.jpg
 

WINGITIS

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WINGITIS

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Here is another Hoffman:

It has a 14.5 foot chord, at 135MPH, its top speed, that is a Reynolds number of 18 Million, way above what XFLR5 can deal with.....

So once you have decided what lift distribution you want you may want to consider your maximum speed and chord to get the Reynolds number down to the scope of the analysis tool you use....

Then take into account the L/Drag area "under the curve" for the different aspect ratios to get the performance you want in your flight envelope........as attached.

Your final plan-form should/could more or less pop out from there!

Note: it sais it uses an "EXTENDED M6" airfoil in the center, it would be nice to know what hes done to the basic M6!?


PFVBX HOFFMAN.jpgAR and LD RATIO.png
 

WonderousMountain

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The original spitfire was to have sharp wingtips,
It was rejected & they were told to use round tips.
Instead they curved the whole leading edge. Next,
A lower wing loading was requested, so the trailing
Edge was plumped, by the third modification, it was
a very nice curve. I think french curves were used.
It is not to any formula whatever. Just very good deals.
 

WINGITIS

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Then there are a few different versions of the Spitfire wingtips you could perhaps superimpose to get the tip controls with the area and look you want:

Super Spitfire wing tip EDIT.png
 

WINGITIS

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The original spitfire was to have sharp wingtips,
It was rejected & they were told to use round tips.
Instead they curved the whole leading edge. Next,
A lower wing loading was requested, so the trailing
Edge was plumped, by the third modification, it was
a very nice curve. I think french curves were used.
It is not to any formula whatever. Just very good deals.
I agree in that final version i posted I liked the wing drawing component best!
 

cluttonfred

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That pic is five years old and I reached out to Mid-Atlantic Air Museum and they said that no restoration work has been done on the Arup at all as of yet. It is very appealing to think that you could build this as a rectangular wing with essentially just the shape of the wingtips and trailing edge defining the Arup shape. I'm going to have to play with that to see what I can come up with.

Someone with lots of interest should visit and start the camera. Before it is covered up.
 

WINGITIS

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It might be easier to SNAFFLE that ARUP and restore it to flying condition than design/building from scratch, I am sure there would be less hours in total....

It may be FREE if they agree with your restoration plan/flying/show schedule etc etc...

I am starting to like them now....you chaps have corrupted me!!!!!!!!!!!!!!!!

Do you live near there CluttonFred?
 

WINGITIS

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That pic is five years old and I reached out to Mid-Atlantic Air Museum and they said that no restoration work has been done on the Arup at all as of yet. It is very appealing to think that you could build this as a rectangular wing with essentially just the shape of the wingtips and trailing edge defining the Arup shape. I'm going to have to play with that to see what I can come up with.
I am pretty sure the Jodel wing planform was setup to be sort of close to a similar lift distribution as the Spity but with simple construction, you could just extend the line of the Ailerons back into the C/Line and that may do it?

Jodel WING.jpg
 

mm4440

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Hi back in the 1970s I owned an Arup S2 replica (I did not build it.) I spoke to Milt Hatfield, one of the Arup's original pilots on the phone. Milt built an ultralight version with a simplified planform with straight edges. I think he called it "The Little Bird". If you search sport Aviation back issues you will find the original Arup article that mine was built from. There was also an article on Milt's craft. I was on the east coast at the time and the Arup pictured might be my former replica.
 
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