Wing design for a Mig 21

[Willmsy]

Hey all I am working on a EDF Mig-21 and I need help in the design of the wings. I understand how lift works but I have never designed a "wing" for an airplane/jet.

Any help would be greatly appreciated.

Thanks

Matt

[JetPlaneFlyer]

I assume you are wondering what airfoil to use?

The airfoil to use probably depends on your method of construction more than any other factor, especially with a low aspect ratio delta where airfoil is relatively unimportant.

If your building from sheet foam then a flat plate with the edges rounded off will work well ok. If you are doing a built up wing then a 'proper' airfoil may as well be used. On my freeflight Mig 21 I thinned down the good old Clark Y to 5%, this worked fine.

You can see my Mig-21 and download the plan here: http://www.ffscale.co.uk/plans9.htm

Steve

[Willmsy]

Thanks

[BMatthews]

The biggest issue with a Mig21 model will be the wing loading. There's a lot of model resting on those little delta wings. You may want to fudge the design of your EDF version a little at the root and a lot at the tip and give it a little more span all at the same time. If you do this without getting carried away you should be able to give it another 25% while not ruining the looks of the model.

[JetPlaneFlyer]

The biggest issue with a Mig21 model will be the wing loading. There's a lot of model resting on those little delta wings. You may want to fudge the design of your EDF version a little at the root and a lot at the tip and give it a little more span all at the same time. If you do this without getting carried away you should be able to give it another 25% while not ruining the looks of the model.

Probably good advise. The wing on the Fishbed does actually have reasonable area, but a little increase would certainly do no harm. I'd keep the shape the same and just scale up in proportion (widening the tips disproportionately would spoil the delta look IMHO)
My freeflight Mig is 100% accurate to scale (or as near as i can make it with the constraints of stick and tissue construction). The wings and tail surfaces are all scale and it flies fine, no unusual habits.. However my model was freeflight and does not have to carry R/C gear, batteries etc.

[BMatthews]

That's the thing... There's a LOT of fuselage and if it doesn't contain mostly air then the wing loading will suffer. Your Rapier version follows that plan so it worked out. An RC one could do it but only with great care I suspect.