Light air outhaul adjustment

altair

Member
I read in the SF Bible that the outhaul needs to be pulled snug in light air. I thought you wanted a baggy sail in light air. Could someone explain why you would want a snug outhaul in light air.
 
altair said:
I read in the SF Bible that the outhaul needs to be pulled snug in light air. I thought you wanted a baggy sail in light air. Could someone explain why you would want a snug outhaul in light air.

There are two possible explanations...

The aerodynamic engineers will tell you that to maintain laminar flow the angle of attack and the curvature of the sail must be optimized to ensure that the Reynolds numbers for viscous and non-viscous flow are not inconsistent with the formation of vortices typical of induced separation in the boundary layer and that reducing the draft in light air will mitigate the impact of Tollmein-Schlichting instabilities in the separation bubble.

The psychologists will tell you that tweaking the outhaul in light air will reinforce your fantasy that the boat is actually moving at all.
 
Snug is different than tight. Just take up the tension. If it's left too loose the corner tends to flap and allows the sail to actually flatten out in that area and decrease lift. that's not a good thing.
 
Old Geezer said:
There are two possible explanations...

The aerodynamic engineers will tell you that to maintain laminar flow the angle of attack and the curvature of the sail must be optimized to ensure that the Reynolds numbers for viscous and non-viscous flow are not inconsistent with the formation of vortices typical of induced separation in the boundary layer and that reducing the draft in light air will mitigate the impact of Tollmein-Schlichting instabilities in the separation bubble.

The psychologists will tell you that tweaking the outhaul in light air will reinforce your fantasy that the boat is actually moving at all.

OG - Mike has been sick with a cold. He just read your post above. He fell on the floor laughing so hard that he almost coughed up a lung ....
 

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