I know the S4310 airfoil is not a modern airfoil and its pretty thick, but nevertheless ...

Has anyone experience with the S4310?

I am currently looking for a cheap recreation thermal glider for light to medium conditons and got an offer for a 3,8m (149") ship with 2700g (95oz) AUW.
I don't expect high performance behavior from an AVA, Xplorer or Shadow!

How does it perform in comparison to a SD7032, SD7037 or MH32?

Is it worth to think about a glider with the S4310 knowing that it will not have the performance of e.g. an AG24/25/26 or other comparable high performance airfoils?

Thanks and regards, Tom

http://airfoiltools.com/airfoil/deta...rfoil=s4310-il

http://airfoiltools.com/airfoil/details?airfoil=mh32-il

http://airfoiltools.com/airfoil/deta...foil=sd7037-il

http://airfoiltools.com/airfoil/deta...foil=sd7032-il

I don't think you should worry too much about the airfoil performance in comparison to some of the newer competition airfoils. Many older designs can still hold their own and performance is much more dependent upon pilot, set up and construction.

How much area does it have? Might be good to have the relevant Reynolds numbers in hand when making the evaluation. When the Re goes up, thicker airfoils have less of a performance penalty, in general.

Approximate rules of thumb for Re:
-speed in feet per second at wing Cl of 1 is about 7 times the square root of the wing loading in ounces per square foot, but I seem to recall maybe it's more like 7.3
- Re is something like 532 times the chord in inches times the speed in feet per second
-actual Re in steady flight will be proportional to one over the square root of the Cl

In addition to the Reynolds number effect, the max lift coefficient desired is different depending on the aspect ratio. If you have an aspect ratio of 8 (very low for something this size), then you don't need as much as if the aspect ratio was 18 or 20. IF you go to a CL of 1 on a wing that has an AR of 8, you will have a lot of induced drag.

For recreational use, I would imagine this airfoil would be fine on something so large, assuming everything else about it is good.

Why the S4310?

Consider a s4233 airfoil. Ive flown one for years on a 3 meter
poly ship w/a 9" chord and it slows down nice and has legs when you need it to. It would also make a good replacement for a scale ship as well.

The S-4083 is a good one too, I have it on a CR Climmax and it can do it all.

S-4083's performance in a Climmax doesn't tell you a whole lot about how it would be in something MUCH larger. The 4310 is thicker and therefore better structurally. The 4233 is even better structurally. On these larger gliders, there is less of an aerodynamic penalty for the thicker foils.

If I had Profili working again I could give you more specific info.

I seem to remember a 3m ARF with a S-4083. I want to build an Xingu with a 4083 instead of an E-387. I learned something a couple week's ago, the Legionair 140 has an 8% airfoil and has some serious inter-thermal speed.

I'm not saying that the 4083 wouldn't work, just that you can't tell from a small model.

I had a Wizard many years ago. It was a 2 meter RES, or maybe just RE. It had a thin, flat bottomed airfoil that was considerably faster than the usual ones.

Guys, the glider on offer to Tom has the airfoil stated, it is not an optional situation with airfoils.

Does anyone have any kind of rc sailplane experience with the airfoil suggested?

Originally Posted by atmosteve

Guys, the glider on offer to Tom has the airfoil stated, it is not an optional situation with airfoils.

Does anyone have any kind of rc sailplane experience with the airfoil suggested?

Thanks for clarification Steve !

I am thinking about the Kranich from SMC Gerten (Kranich = crane).

Cheers, Tom

Just make sure it doesn't have the shrunk tail disease. Many gliders have v-tails that are too small.

For this very high aspect ratio glider, with a moderately high wing loading, the 4310 may be better than the AG foils, because it has a higher lift coefficient. I think if we can believe the plots that jrs123 provided, it may be a decent performer. The thickness will help structurally on such a long skinny wing, though really it ought to be thinned out along the span so that it is relatively thin at the tips.

Originally Posted by lincoln

Just make sure it doesn't have the shrunk tail disease. Many gliders have v-tails that are too small.

For this very high aspect ratio glider, with a moderately high wing loading, the 4310 may be better than the AG foils, because it has a higher lift coefficient. I think if we can believe the plots that jrs123 provided, it may be a decent performer. The thickness will help structurally on such a long skinny wing, though really it ought to be thinned out along the span so that it is relatively thin at the tips.

Why couldn't you just humanly admit that you have had no real or actual experience with either building or flying any model aircraft with this airfoil, Instead of some half baked extrapolation to gain face. Is it that hard, to be honest?

"atmosteve", if you write at least 2-3 posts more than "lincoln", (preferably sarcastic and malicious) then you catch him within 1 year in the number of posted messages. For it seems to be the only reason that you post.
But, unless you have something useful to the discussion, I think, however, that you can keep quiet.
Excuse the rest of you that I did not add anything to the topic, but I think it seems like atmosteve has other intentions than to be helpful in threads that he participates in.

/Ville