Sail Angle to the Wind

Discussion in 'Multihulls' started by Fanie, Oct 17, 2018.

  1. Fanie
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    Fanie Fanie

    One must never assume anything is optimized, or has reached it's limits. Not too long ago it was assumed ridiculous that one can fly... today it is taken for granted, like TV. And not too long before that the earth was flat, and if you said otherwise the holy church would burn you alive. My forefathers came to Sick Africa on the trade winds because they assumed one cannot sail to wind. Well, it was impossible back then, and if you said otherwise you'd be frowned upon.
    In the same manner is perpetual energy possible, but not for you, because you are a slave for the system and you are there to pay. That is why you are taught to assume prescribed limits beyond which you are not allowed.
     
  2. CT249
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    CT249 Senior Member

    Seriously? You're calling me "a slave to the system" and liking me to a flat earther, because I'm not falling over myself to believe that "your" rig, which is an old idea, is better than every other rig that the millions of sailors before you have created? You really reckon that I should believe one inexperienced guy on the internet instead of those who have spent their life sailing, who have spent their careers developing rigs, and those who have done wind tunnel research, computer research, and actually proven their sailing ability on the water? That is not just insulting, it's illogical.

    Your assumption that your ideas are being rejected because they are new is completely wrong. You've shown nothing new. You're basically using lateen rigs, which are ancient in conception and used on one of the world's most popular sailing dinghies. Heavily raked rigs, biplane rigs etc have been around for ages. Some of us (windsurfers) have been using such effects to achieve actual lift-off for decades, so for you to accuse people of being flat-earthers is bizarre. The effect is already known, already used, and also known to have limits and counter-effects.

    In windsurfers, by the way, we take the rake OUT of the rigs and sheet on to prevent nosediving, which indicates that a heavily raked leading edge isn't lifting the bow. Science says the same thing, as Mikko Brummer has been kind enough to demonstrate with his CFD studies on this forum. Why should we insult tens of thousands of windsurfers and experts like Mikko by believing that they are wrong and you are right?

    You referred to the creation of flight so it seems relevant to mention that the men who achieved powered and controlled man-powered flight had the opposite attitude to yours. They learned from those who had gone before. They respected them. They had open minds and they didn't assume that they were right and that everyone else was wrong.
     
    Last edited: Oct 18, 2018
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  3. upchurchmr
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    upchurchmr Senior Member

    Fanie,

    These ideas can work - to a limited degree.
    Check out the Aft Mast Thread and Bi-plane Rig Thread for some extensive discussion.

    But please don't get carried away.
    Attacking because you brought up Perpetual Energy which CT did not. You are going to get dismissed as a crank with that argument unless you have a new theory of energy with some new facts.

    Nothing with a sail up will have no healing.
    Flat sails? Works for some part of a sails life with high stretch material- just not well.

    Let us know how much the masts weight when you build the boat - I hope they don't sink the stern. A dowel rod in the shop is not the same as a real mast.

    I believe you can get your idea to sail.
    And it might perform well enough to suit yourself
    But CT has some very good points, if you are going to compare to current and even past designs.

    Good luck
     
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  4. Tiny Turnip
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    Tiny Turnip Senior Member

    Surely there an issue here between the angle to the wind at which the sail generates power, compared to the angle to the wind at which the boat is able to sail in water, leeway and all? Fanie - your model shots show the sails appearing to generate power close to the wind, but they have a 'perfect keel' in that they are not moving. In a body of water, on a model boat, are they not likely to be blown backwards, despite making a foil and generating power?
    Ice boats can sail extremely close to the wind on account of their very very good keel effect from the runners on the ice.
    CT - totally with the battened sails.

    Adrian
     
  5. Fanie
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    Fanie Fanie

    To make the model work I mounted 4 roller bearings on the sides and it sits on a solar panel. Without wind it does not move forward or backward. The model rolls relative easy.
    upload_2018-10-20_19-6-45.png

    Set up like this, if it points too much into the wind it rolls backwards, and by trimming the angle you reach the point where it starts rolling forward.
    I use only the one sail because the wind tunnel (fan) is not big enough to make both sails perform the same.
     
  6. Fanie
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    Fanie Fanie

    Hi Tiny Turnip, it does not matter if someone disagrees with me or not. When I joined the forum some years ago, there were even then still resistance against mutihulls and many of the discussions were about which is best. It seems that there is huge resistance when ever something different is introduced, perhaps it is because everyone has to get back to the drawing board if a potential threat looms.

    Re unlimited or perpetual energy. Wars are waged just for the resources in other countries. It's about the real god of the world, money. Do you really think they will allow anyone to make something that is a threat to their lifestyle ? It's been done already, and it is murdered as fast as possible before it gets out there.

    Infinite Energy, But Not For The Masses | Andrew Johnson

    If perpetual enery does not exist, how come the earth is still here. Think about it.
    Would you like me to post a picture or two of the alien craft flying around here ? I don't see them filling up at the pump...
     
  7. Fanie
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    Fanie Fanie

    One of the days the wife and I sailed with the little tri on the Vaal, which was more of a drum that a boat, there was a big mono bearing down on us. The wife said this boat was following us. I trimmed the sail and moved our weight forward and she took off. A while later the big boat turned around as they were falling far behind.
    That afternoon when we came back to the marina there was a furious idiot on the shore looking for the motor on the tri which sailed away from him. He was furious and shouted this is what Africans in Africa used to sail with for thousands of years. Reminds me of Fred.

    Living The Dream On A Low Budget Pt. 5 - Jules Tells Off Boatyard Owner
     
  8. Fanie
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    Fanie Fanie

    You make assumptions which I never did do. The first time I saw the aft mast was when Brian Island posted on it. Nobody yet have taken the time to refine it, except perhaps me. I have seen some rather half-hearted attempts and poorly working variations of them. I built a little boat to test it with and founded some interesting characteristics, for one there is less heel and the sails make lift. That is what I'm sharing, not claiming I am the wonderful inventor of anything you are accusing me of.
    Lateen rig - “A triangular sail hung on a long yard that is attached at an angle to the top of a short mast”, I fail to see the close resemblance.

    I think you just came here looking for an argument and to discredit what I'm dong.
     
  9. upchurchmr
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    upchurchmr Senior Member

    Fannie,

    I was always waiting for some report on your tri.
    Looked good
    Do you have some kind of a link?
     
  10. Fanie
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    Fanie Fanie

    upload_2018-10-21_2-50-24.jpeg
     
  11. upchurchmr
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    upchurchmr Senior Member

    There are idiots everywhere.
    Didn't get that you ever made a report on your tri?
     
  12. CT249
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    CT249 Senior Member

    No, I came here to discuss rig design and you responded by throwing around lame insults. It's illogical that you start throwing insults around when anyone dares to raise technical issues with your design, when you yourself insult others with your claim that earlier mast-aft rigs were "half-hearted attempts" and "poorly working". If you're going to sling such insults at other mast-aft rig creators then you can hardly complain when people make reasoned technical comments about your rig.

    On what grounds can you insult people like Gary Hoyt, a world champion sailor who spent a lot of time more working on his Delta rig than you've done on yours? What gives you the right to claim that he hadn't taken the time to refine the idea? Have you seen the boat? On what factual basis do you claim it was unrefined? Why is it OK for you to insult the efforts of Hoyt, Bolger etc but not OK for anyone to comment on your rig?

    You still haven't actually proven any of these characteristics you claim the rig has. Any rig can have low heeling moment if you give make it low aspect, but that just increases induced drag. There is no proof that your rig actually lifts - why should we believe your "tests" when the greater expertise of people like Mikka and the enormously greater practical experience of many sailors prove that there's no reason why it should?

    As far as more detailed claims go, the spinnaker appears to have a major flaw in that it doesn't seem to allow for any variation on sheeting angle, so it can only go dead downwind which is a slow point of sail and only offers very limited variation in course angles. Secondly, your spinnaker only appears to work with stalled airflow - it's very hard to see how it could develop normal luff-to-leach airflow.

    By the way, I just ran some "tests" like yours with a RC model yacht. The sails will appear to stay trimmed to within about 20 degrees of the true wind - however in real life the same very efficient, modern, deep-keeled RG65 hull design can only sail at about 45 degrees to the true wind. That underlines the issues with simplistic static model testing.

    Ps - Yes, your spars are in a different place to a lateen rig but aerodynamically, your rig appears to be similar because both have steeply sloping luffs, low aspect ratios and very open leaches.
     
    Last edited: Oct 21, 2018
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  13. Fanie
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    Fanie Fanie

    I have e-mailed another engineer end explained what I had in mind - which is what I am criticized here by certain individuals for. His reply was -

    In general, I think your idea works. The lifting sail makes sense. I think the multihulls are an essential component of that plan. You will need to limit any vessel heel to ensure the sail directs force upward. Kudos for sticking to the multihulls for that.

    There is a sailing boat that was designed to break the speed record. It employed a similar strategy of lifting sails. You might find that design useful for some further inspiration.

    http://sailrocket.com/
    Quote from the link -

    Sailrocket 2, which smashed the world speed sailing record by the biggest margins in its history, will go on display at this years Advanced Engineering Show in Birmingham on the 4th and 5th of November. She will be accompanied by the team that sailed her at over 65 knots (75+ MPH) down the record course in Walvis Bay, Namibia.


    During an amazing two-week period in November 2012, Sailrocket 2 broke the Outright speed sailing record three times and also smashed the nautical mile world record. She demonstrated incredible efficiency sailing at over 2.4 times the speed of the wind in an open, natural harbour.


    The totally unique craft, representing 11 years work by the team is a hybrid blend of aviation and hydrodynamic know-how. She is based on a radical concept that removes all the overturning forces associated with sailing boats and is as stable in the air as she is in the water.


    The super powerful and efficient craft was designed with the sole purpose of breaking through sailings "sound barrier". With conventional hydro-foils, at speeds around the low to mid 50 knot range, the pressures involved cause water to boil on contact in a phenomenon called cavitation. This offers a brick wall of drag. Sailrocket 2 was developed to have the power to test radical new foil shapes to overcome this phenomena and prove that sail powered boats could go way beyond conventional limits. She remains the only sailing boat in history to have done this.


    This will be the first time that Sailrocket 2 has gone on full public display since she broke the record three years ago. She will be set up exactly as she was the day she set the current record.


    Sailrocket 2 was designed and built in the UK and will be brought to you courtesy of some of those who helped make her a reality, GURIT, FORMAPLEX and AEROTROPE.


    AEROTROPE was the primary design office behind both Sailrocket 1 and 2. Both boats were built using GURIT composite materials throughout. FORMAPLEX provided tooling and complete CNC milled foils for SR2’s record breaking session.
     
  14. Fanie
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    Fanie Fanie

    There is another phenomena which has not been addressed much which may become a reality and that is sails generating their own wind. If you watch video's with wing/foil sails it is briefly mentioned here and there, implicating the phenomena is recognized but not perhaps actively studied or pursued yet.

    Any boat can perform only to the extent where forces created as a result of resistance brakes it's speed, and in current sails it is the leeward hull being pushed into the water, which creates more resistance, and if more force is applied the hull sinks and the boat pitchpole.

    If a sail makes lift instead of a down force, then this limitation is reduced. It does not matter how great a world champion you are, the limitations on the current equipment is what is limiting.

    The current limited angle to wind is the result of the sails now, but there is nothing that prevents new development for sails that could outperform the current, and which may well offer not only better performance, but sailing a lot closer to wind.

    The worst limitations that hamper any form of development currently is this British / American / Zionist disaster which is forcing the Western world under communism, which has the direct effect of retarding any form of development by especially individuals. We experience this disaster daily in Sick Africa.
     

  15. Fanie
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    Fanie Fanie

    And I forgot to mention something else. Everything is not always a maximum speed requirement, there are many applications where speed is not the most prominent requirement, and where direction to wind may well be more important. When one fish for instance, it will be a lot more convenient to be able to sail closer to wind and stay on course than trying to zig-zag to follow a coastline.
     
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