Either you have good numbers based on airfoils that were designed for use in cords close to your particular application, or you have terrible figures to struggle with.

When you are dealing with something huge, Reynolds will play a little nicer. All I was saying is that dealing with things that are model-sized... well, we are all screwed by Reynolds issues. We fly in "soup" compared to airfoil effectiveness of a 4 meter sail plane going into competitions.

Scale effect: RN: cord[inches])X(speed[mph])X780 ... as we know AR: high AR reduces stall angle, but lowers the RN. Scaled foils produce low RN and therefore very low CL. Lower stall AOA & much greater profile drag (typically double or more). So unless you have a foil technology that is as effective as the Eppler series, it will be the same as picking through a pile of bald tires to use for tomorrows NASCAR qualifying.

Making Reynolds Number work for you... just isn't something you have control over. Either your foil allows you to get good numbers, or nothing.