On Tuesday, August 26, 2014 12:50:01 PM UTC-4, wrote:
What about total weight of glider? For example, in dolphin-style flight.



50kg/m2 for Diana2 and ASW27 doesn't mean finaly the same L/D



Regards

Andrzej

L/D is driven by geometry and any differences between the 2 gliders described would be determined by that.
There is a small change that does not follow the classic quadratic due to the effect of Reynolds number. Many(most?) of the airfoils in use have lower Cd as Reynolds number increases, other variables being constant. Most analysis ignores this because it is very hard to measure. It is reasonable to expect that they may respond differently, especially given the smaller chord of the Diana 2 wing.
Just to confuse things a bit more.
UH