J24 (Sail No. 4239) Dartmouth |
29er GBR 074 Tynemouth |
Laurent Giles 'Jolly Boat' Exeter |
List classes of boat for sale |
Favourite Photos |
Post Reply | Page <1234 1313> |
Author | |
Blobby
Really should get out more Joined: 07 May 04 Location: Australia Online Status: Offline Posts: 779 |
Post Options
Quote Reply
Topic: Favourite Photos Posted: 14 Jan 05 at 8:52am |
The big splash on the right must be where the helm / crew landed - 7m away from the back end of the boat...now that is fast...
|
|
Doctor Clifford
Far too distracted from work Joined: 16 Mar 04 Location: Scotland Online Status: Offline Posts: 243 |
Post Options Quote Reply Posted: 14 Jan 05 at 9:30am |
thought you ewnt to university??!! 'id of been'? (only joking, beofre you fire one back!) |
|
regards
Dr. Clifford take two tablets twice daily |
|
sailor girl
Really should get out more Joined: 13 Jun 04 Location: Spain Online Status: Offline Posts: 1031 |
Post Options Quote Reply Posted: 14 Jan 05 at 10:47am |
what's ewnt mean!!! 'went'????
and beofre is that by any chance an anogram of before?! |
|
Sailor Girl, Queen Of The Forum!
|
|
Lucy Lee
Far too distracted from work Joined: 17 Mar 04 Location: United Kingdom Online Status: Offline Posts: 276 |
Post Options Quote Reply Posted: 14 Jan 05 at 7:55pm |
er, wow. Check out their very very groovy rudder, which has some pretty amazing features like the short chord at the point where it pierces the surface to reduce ccavitation at high speed. I recon thats the most amazing foil I've seen since the hydrofoiling moths. I know what I'll be making for my next cherub rudder. |
|
Fly Cherub!
|
|
Brian
Really should get out more Joined: 27 Sep 04 Location: Ireland Online Status: Offline Posts: 503 |
Post Options Quote Reply Posted: 14 Jan 05 at 10:14pm |
ummm yeah... i understand that im sorry lucy i havnt really a clue wat u just said, im not very knowledgeable on anything to do with sailing as a matter of fact. i can see that the rudder is a funky shape alright but i dont really get what it would do, much obliged if u could explain? (i know what cavitation is,i think, but not how the rope would stop it) |
|
Jamie
Posting king Joined: 12 Jul 04 Location: United Kingdom Online Status: Offline Posts: 164 |
Post Options Quote Reply Posted: 14 Jan 05 at 10:42pm |
I'm fairly sure that "short chord" is a reference to the width of the rudder at that point. - you will see the concave curve on the top of the rudder making it a shorter shord at that point. Nothing to do with rope. Of course I may just have made a fool of myself there. |
|
Bruce Starbuck
Posting king Joined: 14 Sep 04 Location: United Kingdom Online Status: Offline Posts: 124 |
Post Options Quote Reply Posted: 14 Jan 05 at 10:51pm |
Chord is the straight line distance between the leading and trailing edges of a foil (or sail). Cord is another name for rope!
|
|
maxim
Posting king Joined: 25 Nov 04 Location: United Kingdom Online Status: Offline Posts: 127 |
Post Options Quote Reply Posted: 14 Jan 05 at 10:55pm |
And could you possibly explain what cavitation is...
(I'm not a marine engineer) Max |
|
Bruce Starbuck
Posting king Joined: 14 Sep 04 Location: United Kingdom Online Status: Offline Posts: 124 |
Post Options Quote Reply Posted: 14 Jan 05 at 11:19pm |
Cavitation is the rapid formation and collapse of vapour pockets in a flowing liquid in regions of very low pressure. This most often happens when water boils at normal temperatures due to very low pressure on propeller blades. This doesn't happen on dinghy foils. |
|
Bruce Starbuck
Posting king Joined: 14 Sep 04 Location: United Kingdom Online Status: Offline Posts: 124 |
Post Options Quote Reply Posted: 14 Jan 05 at 11:37pm |
I think when a rudder stalls, it's due to the water flow detatching and air being sucked down the low pressure side from the surface, and is called aeration, or something like that. A dinghy's never going fast enough to boil the water, so cavitation is a commonly used misnomer in this case. Quite a few classes have rudders with a narrow chord where they pierce the surface. The 470s have been doing it for years. Not sure it makes a huge difference, and it's quite a test of foil building to go making it narrower right at the point where it needs the most strength!
|
|
Post Reply | Page <1234 1313> |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |