tag:blogger.com,1999:blog-37035807.post5263623561402012663..comments2023-07-26T08:59:24.256-05:00Comments on My Farrier F-22 trimaran boat build: Fairing the daggerboard and rudder bladesGKhttp://www.blogger.com/profile/06292931946454267894noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-37035807.post-73031942401521904762009-04-12T09:47:00.000-05:002009-04-12T09:47:00.000-05:00I just found this common sense comment on hummmmmm...I just found this common sense comment on hummmmmm.<BR/>http://www.j24class.org/usa/tips/humm.htm<BR/>GrantGKhttps://www.blogger.com/profile/06292931946454267894noreply@blogger.comtag:blogger.com,1999:blog-37035807.post-28456294916503380672009-04-12T07:00:00.000-05:002009-04-12T07:00:00.000-05:00I just had a look at the i550 design and pictures....I just had a look at the i550 design and pictures. What a wonderful design idea. This boat would have been on my short list when I was looking, if I had known about it.<BR/><BR/>I'm still fairing the foils. The whole point of it all is to keep the flow of water laminar around the daggerboard and rudder. So, I am concentrating on first getting them fair and smooth. The perfect foil would have the sharp point but is not practical. If the flat on the trailing edge is too thick (>2mm) I can shape as in the posted picture. From my research this seems to be the best engineering compromise to delaying the onset of turbulence at that point.GKhttps://www.blogger.com/profile/06292931946454267894noreply@blogger.comtag:blogger.com,1999:blog-37035807.post-16247249514556715272009-04-09T08:53:00.000-05:002009-04-09T08:53:00.000-05:00Grant:Did you find an answer to this? I am buildin...Grant:<BR/>Did you find an answer to this? I am building an i550 (planing hull 5.5m sportboat) and I would love to know the answer so I know how to prepare my foils.Anonymoushttps://www.blogger.com/profile/14294779090461738095noreply@blogger.comtag:blogger.com,1999:blog-37035807.post-19517354053673125382009-04-07T16:14:00.000-05:002009-04-07T16:14:00.000-05:00Thanks Jim, that makes sense. I'll try looking th...Thanks Jim, that makes sense. I'll try looking that up.<BR/>GrantGKhttps://www.blogger.com/profile/06292931946454267894noreply@blogger.comtag:blogger.com,1999:blog-37035807.post-75540847256750132932009-04-06T16:08:00.000-05:002009-04-06T16:08:00.000-05:00Hi Grant , the desirable trailing edge thickness i...Hi Grant , the desirable trailing edge thickness is actually a function of the chord of the foil - can't remember the exact number off the top of my head ( If you are interested the Marchaj book "The Aerohydrodynamics of Sailing" is informative ) So I think the rudder t.e. needs to be down below the 2mm mark but the centreboard can be thicker because it is wider . All the best . Regards , Jim Buckland .Anonymousnoreply@blogger.com