On Mar 29, 4:35*pm, Eric Greenwell wrote:
Dan G wrote:
On 28 Mar, 01:59, Brad wrote:
As a guy who has flown thick airfoil ships and currrently owns a ship
with a 17% airfoil, I am curious what kind of performance in climb I
might see with a 14% airfoil section.

Someone on here mentioned a presentation by Loek Boermans at the
recent SSA conference, where he stated that modern, thin, laminar-flow
sections don't climb as well as they theoretically should in bumpy
gusty thermals.

I attended Boerman's lecture. The problem isn't thin, laminar flow
airfoils in general, but some specific designs over the last two decades
or so that have a "flat spot" in the lift coefficient (Cl) curve as the
angle of attack (AOA) approaches stall. Normally, the Cl increases with
increasing AOA, but in the flat spot region, it remains constant (or
nearly so) even as the AOA increases. Past this region, Cl begins to
increase again with AOA at the usual rate.

Thanks Eric. Which are the specific designs? The likes of the LS7/
DG600/ASW24?