Need a big glider airfoil
I plan on scratch building an EPP sailplane, 4.3 meter wingspan. So far I am thinking about using a sd7037 or s3021 airfoil, but Im not sure which is better suited to a plane of this size. I expect the final weight to be around 90 - 100 oz's. Could anyone suggest some preliminary wing parameters (chord, thickness, root). Also, the wing will be built as 2 pieces... where each half is composed of 2 panels. So, its possible to maybe use a different airfoil at the tip panel.
Mainly, I dont really know much about bigger planes, so any advice would help alot.
Thx in advance