I am building balsa free flight gliders with a chord of 0.10 meters and a velocity of around 3 meters per second. This works out to a Reynolds number of around 15,000.
The wings are around 1 meter in span, and are made with the wood grain running lengthwise. They are thin undercambered (no bottom covering) with maximum thickness of 7 mm at 30% of chord from leading edge.
Because of the roughness of the unfinished grain, is my Reynolds more like 50,000, or am I still down in the range where a flat plate might be better?