Sailing questions #1-#4
wrote in message
...
On Dec 3, 11:56 am, "Charles Momsen" wrote:
Why doesn't a keel achieve maximum efficiency with a leeway angle of 0
degrees?
Who says it doesn't?
I would say that a keel which makes ZERO leeway is highly efficient...
super-efficient.... preternaturally efficient!
~A leeway angle of zero degrees means the flow comes head on at the keel.
Since keels are symettric, the net lift is zero and the drag is a quantity
greater than zero. L/D = 0 in that case.
What is a typical angle for maximum efficiency?
Depends on the typical aspect ratio and typical foil section.
Many boats make 3~5 degrees leeway when hard on the wind.
~Correct
Does a catamaran have maximum efficiency at 0 degrees?
No of course not.
~Rethink the question with the new information about leeway angle.
Why?
Because it's a catamaran, not an iceboat.
~~Iceboats and catamarans work on very similar principles in this example.
~
Fresh Breezes- Doug King
|