The glider I am designing has a mission requirement to fly for as much time as possible. It will fly in the low Re range of about 150,000 to 250,000.
While comparing different airfoils I am looking for a high value of Cl^3/2/Cd to get as high endurance as possible and a high Cl/Cd ratio.
Any other parameters I should consider in selecting the airfoil? I am currently considering Wortmann FX 63-137, E61, DAE-31 and Fx-74-c15-140. Any other airfoil suggestions would be appreciated.