On Wednesday, May 26, 2021 at 6:18:51 PM UTC-4, andy l wrote:
On Wednesday, 26 May 2021 at 21:27:23 UTC+1, krasw wrote:
On Wednesday, 26 May 2021 at 22:52:41 UTC+3, soaringjac wrote:
Where would one buy these fences? I was told they are aftermarket mods, but it seems like every ASW-28 has them installed. Where can they be purchased from? I contacted Schleicher but so far have not gotten any response.
"In 2006, a project had been initiated to measure
the loss in overall performance by applying for
example four additional pairs of fences on the
wings of an ASW-28 (Fig. 1). The result was a
decrease in maximum L/D of about 0.25 points
for a singe pair of fences"

https://tu-dresden.de/ing/maschinenw...TS.pdf?lang=en
An airline pilot friend, with an aeronautics degree, said the delta is one of the highest drag shapes there is if the airflow isn't in line.

Even with a winglet on the end, I don't see why airflow over the wing would be directly in line; surely there's bound to be some spanwise element in the flow, hence at some angle to the blade


... I don't see why airflow over the wing would be directly in line; surely there's bound to be some spanwise element in the flow, hence at some angle to the blade.
That's an interesting thought. One could apply some tufting and install a GoPro on the outer edge of the elevator trained onto that area around the aileron. That way, one would know if a fence makes sense or not.

Uli
'AS'