that is a good read -- and easy to understand
One noteworthy point -- RN under 200000 are typical of models - actually larger models than the crazy micro foamy stuf so popular .
This goes to my own thoughts on airfoils for small - really light ,small high powered models - the airfoil data many espouse as critical for good performance --simply does not apply.
In this realm - weight , area and power are the critical factors .
I only mention this because when I see advice on how to fix a grossly overweight small model - by altering airfoil --I wonder if the advice giver ever flew a small overweight model --
I beat the drum for blaming weight as the only real culprit on these models -simply because any other fix -short of higher speed has not shown much, if any success.
There is a good article in a recent Quiet Flyer mag --developed in a tunnel and dealing with low RN . So far the only tunnel info I have seen which seems applicable to small stuff.