Pressures mapped
on the Star
mast, spreaders & boom. The suction area in the topmast shows in
red. The free stream pressure is 101325
Pa - the windward spreader is relatively neutral , the leeward spreader
is lifting slightly.
In this case, the slim and neat mast is
contributing 4,5% of the total drive. Most of the drive comes from
the topmast above the hounds, as witnessed by the simulation. The topmast
of the Star is typically long for a one-design boat (albeit over 100
years old design!), the fractional ratio of the rig being 65%. Shaping
the profile in order to maximize the drive instead of trying to minimize
drag could be wortwhile.