Height of genoa

[cwkemp]

RichH,
Does the short circuit effect refer to flow from windard to leeward underneath the foot of the sail? I can imagine this would disturb the luff to leach flow for quite a distance up from the foot in the largest area of the sail. Thus a seal between foot and deck assures flow across the most powerful part of the sail.
Am I reading you correctly?
I don't have a terrific seal to the deck as , even with the tack shackled to the stem fitting, the clew rides high enough for at least half of the foot to ride above the deck. Does the short circuit condition exist when the sail is not trimmed in real close?
Clint

 

[RichH]

RichH,
Does the short circuit effect refer to flow from windard to leeward underneath the foot of the ....

Correct

I can imagine this would disturb the luff to leach flow for quite a distance up from the foot in the largest area of the sail. Thus a seal between foot and deck assures flow across the most powerful part of the sail.
Am I reading you correctly?

Correct again.... some 'leakage' is expected, especially if the clew is much higher than the tack

I don't have a terrific seal to the deck as , even with the tack shackled to the stem fitting, the clew rides high enough for at least half of the foot to ride above the deck. Does the short circuit condition exist when the sail is not trimmed in real close?

A. the closer the foot to the deck the better effect
B. when less than close hauled, yes the pressure will go from high to low across and under the foot. and thus diminish any so-called Bernoulli Effect in the lower panel sections. However, most of the 'suction peak' on the leeward side occurs more towards the tack/luff than at the leech.