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Induced drag is varies inversely with the square of the speed. That's because lift comes from bending the flow, and you can either bend a little bit of water by a lot, or you can bend a lot of water just a little bit and produce the same lift. At low speed, when there's not much water flowing over the foil, you have to bend the water a lot in order to support the boat. At high speed, there's a lot more water flowing past the foil so it only has to be bent a little to support the boat. Lift-induced drag is due to downwash from bending the flow. The foil flies in a downdraft of its own5 points
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The freestream velocity and the circulation add together. The circulation decreases the velocity on the pressure side and increases the velocity on the suction side. At high lift, the circulation can be high enough to make the flow go backward on the pressure side. Here is the calculated flow around a section of the USA17 wingsail at high lift. The grid is fitted to the streamlines, so it shows the direction of the flow. The dark line coming up under the leading edge is the stagnation streamline. The air to the left and above goes up and around the leading edge, while the air to the4 points
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I saw this thread heading, "Galley equipment" just after downloading some photos during a recent solo overnight. We've owned this galley for over 20 seasons now and it occurred to me that despite countless (seriously) meals, our galley equipment is spare. Much of it - the 60's fashion plate ware (that matches the 60's style Formica), several of the pots and pans and a few of the hand tools - came with the boat, inherited from the PO. I also recognize a Revere fry pan that came from our last boat, which came from our home kitchen,...that one of us 'brought to the marriage', as my part4 points
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I've refined this image as much as I can with Gigapixel AI. for what it's worth, here's the link to my Dropbox file: https://www.dropbox.com/s/r52ivnx0101i2tj/Ineos foil-gigapixel-scale-6_00x.jpeg?dl=0 . Just use the zoom feature. I'll leave it there for a few days.4 points
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Looking at this picture the speed and degree of control re ride height really comes across. I think that the combination of Barker, Goodison and Hutchinson will compliment one another.....i.e. mature, experienced under huge pressure, history of closing out tight regattas (obviously the cup exceeds everything). I hope that come race time they have a fast enough package. ........with the amount of sailing time they have had they'll likely have squeezed the potential out of the design and will not be relying on last minute bodges or gambles. I wish them well.3 points
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My wife does music therapy in a German hospital across the river, among other things. They test the staff there regularly for corona virus. She was last tested on Tuesday and today they called and said she tested positive. My wife is 61 and in good health and is showing no symptoms. I am not in the best of health and I am also symptom free at the moment. My biggest concern is that the last two times in my life that I had a high fever, I got viral myocarditis which has led to a heart attack both times. So I really don't need a fever. The only treatment for viral myocarditis is s3 points
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3 points
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With a free surface, it's the other way around. Induced drag is doubled at the surface compared to a foil that is deeply submerged. The reason is the boundary condition at the surface. With ground effect, there can be no flow through the solid surface. You can model this with a mirror image of the foil on the other side of the surface. Adding the velocity components from the mirror image cancels the velocity component normal to the surface so there's no flow through it. But the tangential velocity components add together at the surface, so the change in velocity parallel to the surfa3 points
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Not only formalities. Today it's about responsibility, importer into EU has to bear full manufactures responsibilities regarding product security and CE compliency.3 points
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This is a key point^^^ Personally I'd be too busy shitting my pants on something like an Extreme 40 to use it to any effect in this race. I scored last year's finishers with PHRF-NW ratings and the results were very interesting: The guys on Educated Guess absolutely sailed the crap out of that boat, to the point that the finished within an hour of a much faster Melges 32, and three hours faster than an F32 that should have clobbered them. The key question is how fast YOU can sail the boat YOU showed up with. Team Pestou is planning to sail an F24-2 and I'm certa3 points
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I'm guessing pretty much any boat that will sail at the front of the R2AK fleet will require a tough, skilled crew that knows their boat very well. Just like fast cars or airplanes if you have to ask basic questions it indicates that you might want to start with something at the lower end of the performance spectrum and work your way up. The ladies on the F27 did a very nice job with realistic expectations and a good, solid boat. Their goal wasn't to win but to perform well in good style. Just because you can afford a Formula 1 car doesn't make you Lewis Hamilton. I've sailed on the Seaca3 points
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She certainly appears to pop up on the foils easily. Very smart-looking boat, although those angular foils stand out against all the smooth curves ...2 points
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I visited the Vendée Globe village today with a friend of mine. We were extremely lucky to see Jérémie Beyou doing a little Q&A session with gests in front of Charal, good questions were asked to Jérémie and we got some informative answers : - V3 foils : the team wanted a mix of the precedent versions, capable of high speeds and high flights like V1 while being self-stabilizing like V2. They took the V1 shape and redesigned the end. Here is a article on the Charal sailing team were he explains it (only in french unfortunatly) : https://www.charalsailingteam.fr/vendee-globe-imoca-chara2 points
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It's hard to walk away from a successful business model.2 points
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That's a misleading way to think about leeway. The reason is the boats are all pointed the same direction, but in nature there's nothing that fixes the heading that way. Instead, the course through the water is determined by the lift-drag ratios of the hydrodynamic and aerodynamic forces, and the heading is whatever is required to get those forces an moments to balance. So it would be more representative to show all three boats sailing the same course, but with their bows pointing in different direction depending on the leeway angle. This is why gybing centerboards don't really do what2 points
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America's Cup: The Simmer-ing threat to Team New Zealand https://i.stuff.co.nz/sport/americas-cup/123177195/americas-cup-the-simmering-threat-to-team-new-zealand2 points
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You seem determined to have a chance at winning. You might look at Gspot's excellent chart and his comments. 2 things will be required: 1. A reasonably fast boat that you can safely push hard in all conditions day and night as well as "human propel" at 3 knots for at least a couple hours. 2. A very skilled crew that has practiced a lot on said boat and can safely sail it to its limits 24/7 in all conditions. Mad Dog was more than reasonably fast which required lots of skill, toughness and some luck. That was an amazing performance. I think a2 points
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And an easy version thats not behind the paywall https://www.youtube.com/embed/iCdSXZKZK7U2 points
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For the record I was not calling you an idiot. From Groucho Marx. Not Karl Marx. Get it? Ha ha? I am not stupid or a cunt and I voted early for Biden. “All people are born alike... except Republicans and Democrats.” - Groucho Marx “Take a Xanax and go fuck yourself.” - me2 points
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I’m surprised the Red Fox 200e hasn’t come up in this thread.2 points
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He could claim that the dark areas are where he was touched by a black person and a depressingly high percentage of his followers would believe it and decry the violence involved.2 points
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Dalton has the incentive to place blame elsewhere because he’s the one who botched it and is now taking the heat. I doubt the message was relayed by whispering in peoples ears so if they emailed the people who left in the “clean out” messages should still exist in some form. I bet it’s not incompetence, I assume they are grinning.2 points
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Anyone see LR out today?? https://www.facebook.com/135173896618023/posts/2015696568565737/?d=n2 points
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Very revealing photo of her hull shape... https://www.instagram.com/p/CGtlrL4ACr2/?igshid=7ctnssr5lc6x2 points
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If Zombie Mitch wakes up looking for brains in the middle of the GOP caucus he's gonna starve.2 points
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Time to focus. So what is available in terms of trackers? Forss, are you still listening? Yours was the best!2 points
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So, just being forthright here.... 20 guys have proposed 20 different options here and none of them are right, and y'all keep coming back to the Harbor 20. So tell dad to go buy a Harbor 20! I know, finding one..... So buy a new one.2 points
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I had one. The most comfortable seats of any car I've owned. Just as well too as, I spent a lot of time waiting for someone to come and fix it.2 points
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Kind of funny, but backwards. More like, the USA has shit in over 50% of the sandbox, wants to maintain its shit coverage but stop anyone else from shitting there, because that's sooo - oo unfair. Mind you I'm in agreement that China and India et al should stop shitting in the sandbox because it's a global problem, but still - logs & motes...2 points
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Hello! I'm proud to introduce you my last creation, Kasala. It's a 18' family cruiser build in plywood epoxy, that I design for my retirement. The boat is equipped with an experimental rotating rig named roto-duplex. This rig was design to produce the same speed with only two main sails from any sector the wind is blowing. So we achieve 4.6 kn on beating at 41° going to 5.5 kn on running at a wind speed of 10/12 kn. It's easy to handle alone but we have all commodity on board to enjoy a small cruising (fresh water tanks, portable toilet, alcohol heater and cooker, four berth ...) . The bo2 points
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The blame lies with the person at the top of the food chain. Always has, always will. Someone associated with ETNZ’s defense fucked up. I don’t think in any way this was a planned attempt to gain an advantage, just a royal fuckup. And like it or not, that falls at the feet of the guy in charge for not making sure his minions had sorted all the details. It makes no difference to me, since travel to NZ isn’t happening, but I hope it all gets sorted out for the Kiwi fans.2 points
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where the hell did you go with it? We all thought your urge to maintain the shit out of something was because of the navy training!2 points
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That has to be the dumbest argument ever made. Sorry, I have just as much right to live here and work to better it, as you have a right to live here and hope it turns into a shithole.2 points