Looking for Glider Airfoils

[shobhit17]

I have been in the hobby for quite sometime and am planning a scratch build glider. I have a few queries to decide on what to build.

1. What is the airfoil suited for slope soaring RC Gliders
2. What is the Airfoil for thermal hunting for gliders

My build is likely to be 2.5 mtrs in span and am looking for an aerofoil where I can provide the required strength on an All Balsa construction.

Thanks

 

[Shurik-1960]

https://disk.yandex.ru/d/OpwybZf7qqA68A - These are the best profiles for models of the Wiesel type.

 

[Piotrsko]

Bad news: there isn't a general all round high performance airfoil. If there were, there would be no arguements as to which one was best. So you have to pick a series of characteristics that you want to favor then pick ordinates that match. I favor NACA 008 but they are thin weak and have a wicked abrupt stall. They do however work really fine for a stressed skin thin wing fast sloper flying inverted in high winds. For starters I suggest a Clark Y variant and a rounded lower nose entry. Flat bottom easy to build and thick enough to be strong and slow, predictable stalls. Super easy to build would be the KFM series of stacked planks

 

[quorneng]

I do agree with Piotrsko there is no wing section or even airframe that is "ideal" for both slope and thermal flying.
For slope a good speed performance and structural strength takes precedence over its weight.
For thermal work high speed is a disadvantage and weight (its sink rate) is important to make best use of weak thermals.
These are just broad considerations as "conditions on the day" may override an ideal configuration,
For an RC plane there is another consideration. It has to stay within sight of you the pilot. Something full size gliders and birds are not so limited.