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Showing content with the highest reputation since 02/09/2021 in Posts

  1. 37 points
    It's pissing down outside and yes, we are back to Level 3. To all those moaning and bitching about it and calling the PM childish names, get a grip, we are the luckiest people in the world right now, to have had a wonderful, normal summer, an Americas Cup regatta, and a government that had the gumption to get on top of the problem early. Meanwhile, here is a bit of rainy day, AC75 action-less filler ...
  2. 19 points
    Wow, if someone gave you a new shitter, you would complain that is smells too nice.... the US gave a billion $'s to each of the major vaccine producers to help them scale up the testing and production. It takes time to scale up the vaccine and get is distributed to the people. The US has started vaccinations and is not on a pace of 1.5 million/day. I am 64 and in the last "Bernal population" category and most likely will not get vaccinated until maybe July. You in NZ will be vaccinated way before us. Our cases have dropped dramatically since the holiday gatherings, but we still have over 1,000/day dying from Covid. You guys live in a bubble of normality that no one else in the world enjoys. You have a few hiccups and use them as excuses to claim the sky is falling. You need to spend some time hauling bodybags out to the refrigerator trucks in a hospital parking lot (because the morgue is full) to give your a dose of reality! My comments are not just direct to you, but the chorus of posters that just do not understand.
  3. 15 points
    One video uploaded, and this YouTuber has smashed it (it's not my video). Top editing.
  4. 14 points
    I just scratch my head over the celebration over his death. I'm not a fan. I didn't listen to him because I didn't find his rhetoric interesting or helpful in our way forward...however.....my dislike certainly doesn't rise to the level of celebrating his death. While I'll not mourn him, I won't celebrate his passing either. A political difference doesn't take me to that level of animosity. There is a human element that would and should rarely find cause to celebrate in another human's suffering and passing. Hitler? Bin Laden? Manson? Perhaps. Certainly not a political difference..........
  5. 14 points
    This has to be one of the most hysterical irrational posts on any internet forum. How can it escalate? The defenders yacht club (RNZYS) is holding weekly sailing series tomorrow. Auckland has gone down to alert level two which allows the racing especially with the pre arranged protocols put in place for exactly this situation that they all expected had a high chance of occurring. The COR is happy to proceed and it's their series to run. Expect to see racing resume on Friday when everyone realises its inevitable. Nice job by the Kiwis and INEOS to have a crack at saving their own interests. Laughable that they have no shame to actually paint a competitor in a bad light for WANTING to go sailing. Get on with it and stop throwing shit.
  6. 14 points
    I can't imagine why a genius such as yourself is not employed by the Government instead of all those tedious scientists with medical qualifications and PhD's and decades of experience. After all what can a collection of people who have spent 30 years studying this exact subject offer that a semi literate sailing forum troll can't after a few minutes at a keyboard.
  7. 14 points
    Data from yesterday's races - no big surprise, but there are some interesting things. I've excluded the first few minutes from Race-1 when INEOS was off the foils. As was obvious during broadcast, the big difference was upwind. In Race-1, LR was not only faster, but pointed higher for a much better VMG: In Race-2, upwind TWAs were similar, but LR was still faster: Downwind VMGs were almost identical in both races, but there is a fascinating difference in leeway. LR seems to have two modes both upwind and downwind - a negative and a positive leeway mode - whereas INEOS has only one upwind and one downwind mode with leeway mostly between 0 and +2 deg: Upwind (Race-1 and Race-2): Downwind (Race-1 and Race-2): As a reminder leeway is used here as the difference in course sailed vs direction of the boat's centerline. Positive leeway means the bow points upwind from the direction of movement, negative leeway is when the bow points downwind of the direction of movement - boat seems to be crabbing windward. Current may interfere with this calculation, but I'd expect mostly the same effect on both boats. I don't think LR's double peak in leeway is because of that. Pitch also changes differently for the two boats. It seems LR pitches forward more as speed increases. upwind pitch in Race-1 was similar, but Race-1 downwind and Race-2 both up/downwind LR pitched forward more. Race-1: Race-2: Some other differences: INEOS also sails about 0.5m higher than LR. I don't know if this is a calibration issue or it's because of pitch angle (I assume the height sensor is on the bow). INEOS also seems to cant the foils out more both upwind and downwind, and there are some minor differences in how they change the cant when tacking or jibing. If anyone interested, I can post these graphs, too. Maybe a bit concerning for INEOS, they actually used the shifts a little better than LR in both Race-1 and Race-2 and still lost.
  8. 14 points
    A bit of a cliché, but fun ...
  9. 14 points
    OK, it sounds like there's some interest in this topic, so here goes. Any engineering effort starts by defining the requirements. From this figure, it looks like the average foil area is 1.64 m^2, and Max Hugen has a lift force of 80 kN, so a good design loading would be 49 kN/m^2. We need the onset of cavitation to be at least 45 kt, and it would be great to be able to get to 50 kt. The foil should be as thick as possible for the cavitation speed, but I haven't worked out how much volume of steel is needed to meet the ballast requirement. Let's see what we get for the thickness and that may help drive the decision as to whether to go with a bulb or not. Let's target 18 kt as the takeoff speed for this first pass around the design spiral. The plots of pressure along the chord show the upper surface in blue and the lower surface in red. (The dashed line shows what the pressures would be if the effects of the boundary layer were not included. The boundary layer displacement thickness is shown added to the shape of the section.) Cp=0 means the local velocity is equal to the freestream velocity. Cp=1 means the flow has been brought to a complete stop. Negative Cp values mean the local velocity is higher than the freestream, and Cp becomes more negative with the square of the local velocity. So long as the pressure remains greater (Cp more positive) than the vapor pressure of water, cavitation cannot occur. So there is a threshold Cp value corresponding to the onset of cavitation. The higher the speed the lower (less negative) this threshold will be. The speed at which the minimum Cp anywhere on the section equals the threshold for vapor pressure is the incipient cavitation speed. That's what I will be using for design. The actual speed at which cavitation bubbles become visible is a few knots higher than that, so this approach is somewhat conservative. I'm going to use the E908 section as a starting point. Will it meet the requirements? The thickness is only 9%. That's not going to make the structures engineers happy, and it's going to require a big bulb. The second plot shows the pressure distribution at half a degree angle of attack and zero degrees of flap deflection. The pressures are fairly flat, and the minimum pressure is at mid chord. This is where cavitation will begin at high speed. But, as shown in the third plot, a modest increase in angle of attack forms a pressure peak on the upper side of the leading edge. This will reach the cavitation threshold at a lower speed. The fourth plot adds the pressures from 0.5 degree angle of attack to show the changes have mostly been at the leading edge. The next two plots show what happens at negative angles of attack. The pressure on the lower surface leading edge drops to being comparable to the upper surface, and then as the angle of attack is lowered further, a pressure peak forms on the underside of the leading edge. This again lowers the speed for the onset of cavitation. The E908 section was designed to use a 20% chord flap, and the next series of plots shows the effect of flap deflection. A +5.8 degree flap deflection, the design value for the E908, increases the lift on nearly the entire section. A modest pressure peak has formed at the hinge line. Deflecting the flap up results in the underside of the hinge line being on the verge of forming a pressure peak. PLots 11 - 13 show what happens when the flap is deflected 10 degrees. There are pressure peaks at both the hinge line and leading edge. Plot 13 shows the pressures at zero flap deflection for comparison. The next figure shows the drag polar plots for these flap deflections. The plot on the left is drag vs lift. In the middle plot, the lines sloping up to the right are lift vs angle of attack. The nearly horizontal lines are the pitching moment curves. On the right is the boundary layer transition location. I've artificially tripped the flow near the leading edge so the boundary layer is fully turbulent. I'll get into laminar flow later. Since the E908 is too thin how about making it thicker? I bumped the thickness up to 12%. The velocities on both surfaces are increased, especially on the lower surface. The upper surface would have increased even more, but there is separation at the trailing edge that reduces the lift. The increased velocity on the upper side means the thicker section will have a lower cavitation onset speed. The final chart shows the cavitation envelopes for all of these configurations. If you know the speed and you know the lift coefficient, then you know what the load is per unit area. The black lines show the loci of constant loading, and are universal. Since the lift has to support the weight, and the side force is constrained by the righting moment from the foil, as a first approximation the lift can be considered to be constant as the speed changes. The heavy red line shows the loading corresponding to the design requirement of 49 kN/m^2. For each of the section shapes, the speed at which the onset of cavitation corresponds to the minimum Cp as the angle of attack changes is plotted vs the lift at each angle of attack. This forms the cavitation envelope for that section. As long as the line corresponding to the loading is inside the envelope, cavitation cannot occur. The flat right-hand side of the envelope is when the minimum cp is in the middle of the section, and it defines the high-speed limit. The top side of the envelope shows how the pressure peak on the upper side of the leading edge leads to a rapid reduction in the cavitation speed as the angle of attack is increased. The bottom side of the envelope is defined by the pressure peak forming on the underside of the leading edge. Where the load line intersects the envelope top side sets the minimum takeoff speed. If the boat tries to take off lower than that speed, cavitation will occur at the leading edge, reducing the lift and increasing the drag. So cavitation is not just a high-speed phenomenon. Even with 10 degrees of flap, the E908 has a takeoff speed that is more than 21 kt. With zero flap it can get up to almost 42 kt, and deflecting the flap up gets it to 43 kt. It doesn't meet the requirements for either takeoff or maximum speed. Increasing the thickness to 12% (peach line) helps a little on takeoff, but makes the high speed limit even worse. So the E908 is not going to work for the AC75. Next, I'll start to modify the E908 to make it more suitable.
  10. 14 points
    Is there any interest in a series of technical posts that would illustrate the issues in foil wing section design by starting with the E908 section in this paper and modifying it to make it more suitable for the AC75? It'd be too long for a single post, but I'm thinking that by giving each stage in the process its own post that it might be more digestible.
  11. 13 points
    To all my Italian friends. You are quit correct to stick to the rules. Some dumb journos in NZ are stirring the pot. I want INEOS to win but not at the expense of rules that all teams agreed to.
  12. 13 points
    Took FRANKIE over to Shilshole today and turned her over to Green Card for some love and attention. I towed my Hadlock 23 Skiff behind so I had a way to get back home. It was strange watching no wake off of FRANKIE and plenty of wake off the skiff.
  13. 13 points
    Bugger, Justin beat me to it! I could see him taking that photo ...
  14. 13 points
    LR's mainsail looks like it's tailored by ....... well, Prada. INEOS' mainsail looks like it's done by Boris Johnson's tailor.
  15. 13 points
    What a bunch of shit! Bind all colors? You fucking idiot, it was written when slavery was thriving and we were slaughtering Native Indians. Did they play it before lynchings? I give Cuban credit, it has no purpose at a sporting event. Bind us? Sheesh. You need to get laid.
  16. 13 points
    Honestly I don't get why LR is considered so much "frivolous", "annoying", "rude". First of all, let's make a step back. ETNZ won the 35th AC with some help from LR, that was COR at the beginning of that campaign. I'm not saying that ETNZ won only because of LR help of course. Still, they gave them their test boat, 20 people (including MS) and all the development they had done since the retirement. According to Chris Draper the flying software loophole was found by LR, and I'm sure they bring a lot of other cool stuff to Bernasconi & Co. LR design team was nearly the same of this edition, plus Marcelino Botin. I'm not saying of course that ETNZ is "in debt". LR got the monohulls, the upwind start and the naming rights for the challengers series. So, from what I recall, the first arguments between LR and ETNZ started with the wind limits. Nothing so serious, and ETNZ basically won. Then the B and C racecourse argument, where all the Challengers were against ETNZ, not only LR. ETNZ fixed that one too, or better saying, the Harbor Master fixed that for ETNZ. Apparently ACE made some mistakes, and all the ACE management, I have to say, has been far from flawless. The Mayo and Calder issue, than the 3 millions stolen in the fake bank account fraud, then the ACE-ETNZ loan to design the new class, then the B and C race course initially banned and then reconfirmed. I'm not saying these are GD errors, he's been cleared from all the allegations I think, but it's impossible to address the ACE managing perfect, and I still think he shouldn't manage both ACE and ETNZ. Many compliant about LR continuous requests to the arbitration panel for the backstays. The first backstays related arbitration is N. 72, dated 4th January 2020. There are 71 arbitration requests before. Every competitor filed interpretation requests, a lot of them, without causing so much nuisance. LR is right in trying to sail without backstays, they can have a real gain in performance, it could be a race-winning innovation. Nobody complained when ETNZ fought for the foils in AC 34, right ? I remember Dennis Conner trying to disqualify KZ-7 in the old days. We're not seeing anything new, a team found something cool and the other tried to copy it / ban it. So why so much spite against LR ? Last but not least, the Ineos yellow card. If your boat get measured and after that you change something, other teams will go after you. I think LR was the first to move against Ineos, but AM would have done the same thing. Or ETNZ should this occur in the Cup match. End of story. UK media went berserk for this, but they have to blame Ineos design team. LR tried the no-backstays configuration during the ACWS exactly for that reason, so they couldn't be reported in the Prada Cup. In the end, LR is fighting just like ETNZ, Ineos and before the elimination AM. So why all this acrimony ?
  17. 12 points
    THIS is awesome.... each green dot is a radio station. click on it and listen to the station. Worldwide...I just spent 20 min listening to Irish pub music from Dublin http://radio.garden/visit/pomona-ny/ALAgnCng
  18. 12 points
    I vote neither option here -I vote race now. What on earth is the release from iain Murray today saying they don't have on water resources.... I've never heard such crap! In the end Prada are playing serious hardball within the rules. They are 4-0 up and any delay for them just gives Ineos time to improve. Why on earth would they do that? I'm an Aucklander - i'd love all races to be sailed with a huge spectator fleet in our amazing harbour, but the fact is in L2 racing can take place - and Prada are well within their rights to want to race. They won't make friends with the tone of their press release - but they have the rules on their side....
  19. 12 points
    UK variant is a higher threat. We’ve been through it here. Very high cases very quickly from a low base, in my little rural area. A neighbour of my age died from it. If you have the chance to suppress it early, ffs take it. Screw delays to the ac, it’s just a boat race.
  20. 12 points
    Some of you whining cunts should fuck off to wherever it is that you think is doing a better job of managing the disease and leave us alone to enjoy the cup
  21. 12 points
    Was listening to my daily QAnon podcast - it’s revolting what the fake SA media don’t want you to know, that the AC is actually run by a cabal of Alinghi fans operating from the basement of a Port Macquaire pizzeria - and the latest conspiracy was revealed: Max Sirena and @MaxHugen are actually the same person - blindingly obvious, same name and nobody has ever seen the two together! He/they have devised a diabolical get-rich-quick scheme, knowing that the anglo-saxon betting money would go to Rita, and then making sure LR’s performance in the RR would be pathetic to scare off any Italian bettor. As a result, he/they are the only ones having bet on LR and will rake in all the jackpot! Only snag is @JALhazmat seems to have smelled a rat, he needs to be dealt with asap
  22. 12 points
    Please just stick to the facts and not your opinion. You have a fundamental misunderstanding of how this all works. The flu is down because of all the hand washing, social distancing, mask wearing, etc... That is a fact! They do not list every sniffle or cough as Covid, it has to be confirmed with a positive test result for Covid. That is a fact! Covid figures are under counted because many asymptomatic people never get tested. That is a fact! Many vaccines require a booster shot in order to maintain immunity, that will be dealt with as needed. That is a fact! There are estimates that maybe 15% of the US population has had Covid, that is no where near the 80% range expected for herd immunity. The pandemic is NOT nearly finished in the US. That is a fact! Would mankind have survived the last century without vaccines, most likely. But with significant changes to our lifespan, medical costs, prosperity, etc... And oh, just imagine how many Native Americans, Incas, Aztecs, Mayans, etc would have survived if they were vaccinated? It is really easy to research your claims before you post them on the internet. Just type it into your browser and see what comes up.
  23. 12 points
    But you have no clue what "commie" actually means. Your use of the word (and "socialist" as well) is a slap in the face for people who suffered under communist or socialist regimes. It is trivializing and does not do justice at all to the real implications of socialism/communism.
  24. 12 points
    ETNZ and INEOS were out practising on Course E this afternoon, with the course marshalls, race buoys and TV cat and 2 choppers, in what I presume was a dress rehearsal for tomorrow. The course was pulled down at 4.30 and both boats came back and de-rigged in the channel before towing back in. LRPP had been out briefly as well, but came back in around 3.
  25. 12 points
    I think it’s a horrible decision. A Gunboat will eat huge amounts of time and money at the yard. There’ll be a lot of maintenance downtime...certainly more than expected. You’d need good full-time crew who are empowered to say “no” to the whims of the 10 owners. The only thing worse than one person who can’t afford their boat is 10 people who can’t afford their boat. Rent, rent, rent. There are several GBs that charter, and their chartering is a fig leaf to justify expensing ownership costs. Translated, that means there’s no need for profitability in the charter business model, so charter rates are well below the amortized cost for a week aboard.