Subject: Re: [harryproa] Re: Design your proa |
From: Arto Hakkarainen |
Date: 5/24/2011, 6:42 AM |
To: harryproa@yahoogroups.com.au |
Reply-to: harryproa@yahoogroups.com.au |
Every foil, be it rudder, sail, wing, board, keel, whatever that has tip has also tip wortex. It is one of the reasons why multi mast vessel performs worse to windward than single mast (there are other reasons too). If foil generates lift it will also create tip wortex at the tip. Tip wortex adds to resistance. The added resistance which also adds fuel consumption has put airplane industry to work a lot to improve the wingtips in order to minimize the tip vortices. See more here: http://en.wikipedia.org/wiki/Wingtip_vortices
Of course if your design goal is not maximum efficiency you may have better results with bigger number of shorter foils but the tip vortices are one design consideration.
Arto
--- On Tue, 5/24/11, tsstproa <bitme1234@yahoo.com> wrote:
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