Sail efficiency = speed gained ?

Discussion in 'Sailboats' started by hprasmus, Sep 3, 2011.

  1. hprasmus
    Joined: Sep 2010
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    hprasmus Junior Member

    Roughly a year ago I asked this forum about the relationship between reduction of skin friction and gained speed. It turned out to be impossible to answer.

    This question is in the same ball park:

    How much will a 5% increase in net sail efficiency contribute to a sailboats speed (below max. hull speed of course) ?


    I have just had results back from CFD-testing that indicates that such performance improvements could be possible by using a different sailbatten configuration than is normally done today.

    AND learning from last years experience: NO, I can not display the idea as I am in the process of preparing a patent application.

    And YES. the CFD-simulation was conducted by a very well respected professional in US.

    For one thing I find it obvious that a 5% efficiency gain would make it possible to reduce the sail area by 5% and thus save on the handicap rating of the boat. Or ?
     
  2. Tim B
    Joined: Jan 2003
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    Tim B Senior Member

    Neither question is impossible. It should be obvious that any increase in efficiency (which you need to define... Here I will use in increase in the drive/drag or drive/sideforce ratios) will result in improved boat speed. How much of an increase is dependent on the boat, and how optimised it was in the first place. I think you need to do some basic Naval Architecture before you start filing patents, because for the scope of what you wish to patent, you really should be at least aware of the implications on performance without having to ask questions here.

    You should also be aware that increasing the driving/sideforce ratio by 5% won't give you 5% on boat speed. That's pretty simple physics, hull-speed doesn't come into it, but V^2 does.

    Do yourself a favour, stop wasting your time and money filing patents for which you don't have the understanding to make a decent case, and do something useful with your life.

    Tim B.
     
  3. idkfa
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    idkfa Senior Member

  4. hprasmus
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    hprasmus Junior Member

    To Tim B

    What an attitude ! It is a simple question, and yes I am not an naval engineer, but if you as an expert, can't answer better than insulting me, I think YOU should search for an other field of occupation ! Thanks
     
  5. BATAAN
    Joined: Apr 2010
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    BATAAN Senior Member

    I assume by your use of battens you are trying to improve shape and airflow to give more net drive by controlling sail shape. If your computer sim says it helps, that is good, but remember that sails stretch and change shape fairly early in their lives and that is the reason they are replaced often by racers. My point is that the real world is not in a computer and the models used to get results are quite simplified to be usable, and many factors come into play that you may not be aware of.
    Build a sail using your ideas and try it alongside an identical boat with same size new sail but the older type. This gives apple/apple comparison and will tell you if you are on the right track.
     
  6. hprasmus
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    hprasmus Junior Member

    Thanks Bataan !

    I have actually already followed your advice, but in a sense in reverse engineering.
    Initially I tried the concept (not so much for comparative speed testing as for practical application issues) on Optimist dinghys. It worked quite well and I then moved to model simulation by CFD.

    So, now I have the positive results and wish to translate them into actual speed benefits. Obviously to save cost from further outsourced engineering.

    Actually a very senior member of this community is involved in this refinement work. At least his company is and I don't think that he knows by now. Just to make you aware that this project is handled very seriously and professionally.

    Thanks
     
  7. CutOnce

    CutOnce Previous Member

    You seem to be interpreting responses you don't like as insulting. It is a common theme here. The other thing I notice is that you are ascribing expert status to someone on the Internet, and that too is a serious potential mistake.

    First, publishing very public claims on Internet web sites about pre-patent technology advances is not done. If you were serious and professional about your patent claim, you would remain silent until the letters patent were granted - in multiple jurisdictions covering all countries where the patent would prove profitable. This is an expense in the order of tens to hundreds of thousands of dollars. Previous employers have done this with technologies I have developed, and I have been through the process in the US, UK and Canada. Although assigned to prior employers, I am a patent holder.

    Patents cover specific implementations of the technology, not the intangible idea behind the specific technology. You submit plans, drawings and an abstract detailing the specific implementation, along with research and references to prior art, clearly delineating how your concept is different, and then patent agents will consider your concept, search for published prior art that may precede your claim (something they do very poorly) and then grant or deny your patent. I think the previous poster's claim that 2% of patents make money is highly overstated.

    Your concept may be valid, and may hold promise - no one here knows enough about the specific implementation to judge. Tim B.'s somewhat direct and uncomfortable opinion is too worth note - he is correct that many factors affect boat speed, ratings and efficiency - and the area your concept claims to address only could apply to one of many factors. There is no one-to-one relationship between sail efficiency and boat speed.

    The information you seek regarding sail efficiency and boat speed is different for every boat and every rig - and the only way to determine this is through real-world testing comparing a rig using your specific implementation against a control sample without the technology across a range of conditions and then developing a data set, analysis and conclusions. What you were asking for was a way to predict results on an unknown technology without actual testing. If people could accurately predict the results of your technology without testing, measurement and analysis, then they would be rendering my whole science and engineering education worthless.

    Obviously, your excitement for your concept has overwhelmed your acknowledgement of the incomplete state of the research your are doing. You've gone from developing a hypothesis to directly proposing a patentable implementation - skipping the interim steps of building a functional real world implementation, testing in target conditions, collecting enough data, performing analysis, publishing your results and having qualified peer review. Your claimed computational fluid analysis is but one early step in the process.

    I'm excited about a possible performance improvement in your implementation - and fully support your ability to protect and gain revenue from it. But your response to an Internet-based comment questioning your assumptions is out of proportion to where you are in the process. Come back when your thesis has been published, showing the credentials of the people doing the peer review, after your patents have been granted and you'll find an attentive, respectful audience here. Until then, you might have to develop a little tougher skin when people (who you don't know and have no idea of their credentials) question your concept.

    Best of luck!

    --
    CutOnce
     
  8. hprasmus
    Joined: Sep 2010
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    hprasmus Junior Member

    Ho CutOnce and others

    I think you and others are quite mistaken about the process of applying for a patent - and getting it. You do NOT need to substantiate a claimed benefit. As an absurd example you could gain a patent for putting wheels on a car. Without specifying how much faster it would move.

    Anyway I do have a very pro patent agency supporting me and we have actually already filed for patent. What I am looking for is substantiation of the effect for sales purposes. Quite simply.

    Thanks
     
  9. CT 249
    Joined: Dec 2004
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    CT 249 Senior Member

    As a caution, the fact that your configuration is not common today obviously doesn't mean the patent is valid. I mention this because many people are not aware of what has been tried in the past.

    This isn't to anyone's discredit. Very few people have, for example, read about Taffy Bowen's walking stick rigs with split battens and pocket luffs, or the '60s Moths that had a metal projection like a gaff to give a squaretop outline and allow tension on the head to be adjusted, or the canting keel and bow rudder described in the 1800s. About the only way to find out all prior art would be to go through every single sailing magazine and development class newsletter ever published. Who can afford to get a patent attorney to do that?

    A classic example is the trapeze. History books almost always say it was developed just before WW2 in International 14s, Kiwis say they did it a couple of years before - but in fact they were described in great detail decades earlier, in the southern hemisphere but well away from NZ, Australia. Another example is the foiler Moth (photographed decades before it was first well known) or the wing-sail Moth (first created about '58).

    In battens one can remember writings about steam-pressurised battens to alter shape (Tornado, Canada), inflatable battens, or sailing with battens with a wire running up the leach so that sail depth could be adjusted. That's just off the top of the head, and I've never actually tried to find anything on them in (for example) the bio of Sandy Douglass, or the Moth class newsletters.

    The number of inventions that are actually reinventions is pretty large, which would be most dispiriting if one had spent tens of thousands on patents that turned out to be worthless.
     
  10. hprasmus
    Joined: Sep 2010
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    hprasmus Junior Member

    Dear CT 249

    This is my first attempt in getting a patent and I am learning (spending) as I go along.
    You are quite right in your stements regarding publication. But then there are many ways to address a specific area of invention. If you do some searched on e.g. espace.net where patents are logged and look for for instance sailboat keels you will find hundreds if not more patents that have have made it. So, it is not only the concept but certainly also the practicalities of the invention that counts.

    Even though my patent has been delivered there is no need for me to disclose further details.

    All in all this is a theoretical question to professionals: how to translate net sail efficiency intt speed gain ? By net I mean that both drag, side force etc. has been taken out of the equation.

    Thanks
     
  11. CutOnce

    CutOnce Previous Member

    You are welcome.

    You are absolutely correct in that benefits do not need to be substantiated. Most are not. I have to admit, I was wrong in posting that many patents are not profitable. They are, but only for "pro patent agencies" like you are using. Patent agencies make good money by filing for and obtaining results with patent claims at the expense of the client. My observation about the lack of patent profitability should have been directed specifically to people owning patents. Patent agencies do not survive if they show their clients how many of their clients actually receive value for their services. Much like lotteries or casinos, patents are a fun way to help sustain dreams of getting rich. You never know who will win.

    The best real-world example I can think of to help you in your quest to substantiate your dreams of profit from your idea would be the Canting Ballast Twin Foil (CBTF) idea owned and marketed by CBTFco. Easily found by searching the Internet, they have implemented a successful technology in the sailing world that is used to enhance performance of extreme high end keelboats used in racing.

    Their concept works, is used in a small proportion of boats and has sold enough to be considered a success. I do not know if they have truly become wealthy from their concept, but they haven't disappeared yet either.

    It appears you are looking for SALES substantiation, not design or scientific commentary, therefore you may be asking on the wrong web site. This is a Boat Design website, not a Boat Marketing web site. I'm sure there are web sites out there for helping people generate sales projections.

    Best of luck!

    --
    CutOnce
     
  12. yipster
    Joined: Oct 2002
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    yipster designer

    filing and paying for a patent is not the same thing and alltogeter i'm suprised 1 out of 50 makes money of a patent

    i had royalty's once without patent, thats possible too. when those eternal royalty's gave payments euro problems
    i told them to gift my royalty's to the blind children at the cote dazur where i too would reside, not very smart

    by filing for you have protection for a paralel entree during some months
    by paying, about 10K for each country you have a patent for 6 years

    at least thats how it works in europe last time i filed a patent
    glad i thought the 10K was to much, specially since i wanted a wider patent than just holland
    becouse now after a decade "my good idea" still has to become implemented
    the filing probably still archived somewhere but the money would have been waisted

    "a different sailbatten configuration" i wonder about. Hereshof already used double layer saill and got banned
    ruling on full, half, type, etc battens is not light eighther from what i've been reading.
    AC cup alinghi expiremented with inflatable battens at the same time i only imagined them few years back
     
  13. hprasmus
    Joined: Sep 2010
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    hprasmus Junior Member

    Yipster,

    Actually, to my surprise, inflateable battens are a fact ! That turned up during the patent agency's screening: http://www.airbattens.com/

    My invention is much less sophisticated (potentially less costly) but works along some of the general ideas, but with a different purpose.

    I am stilling missing some firm indication of converting net sail efficiency to speed gain ?

    Was my assumption that a 5% net efficiency increase could be converted to a reduction of 5 Sqm of a 100 sqm sail incorrect or what ?
     
  14. hprasmus
    Joined: Sep 2010
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    Location: denmark

    hprasmus Junior Member

    Uuuuups, if I keep replying to all responses I will probably get the best posts/view ratio on this forum......

    Could someone kindly help my negative score on 'reputation' ? I am not a bad boy.....
     

  15. CutOnce

    CutOnce Previous Member

    I had read somewhere that an early (earliest?) trapeze implementation was on Thames A-raters in the UK - long before the Kiwis or Aussies. Huge tall rigs, designed to grab high breeze above the tree on the river banks, light winds. Came about one days after a crew member was hanging off the shrouds with their feet on the rail. I can easily see a bored crew member fooling around and doing this.

    Like most things, originality is directly proportional to the obscurity of the source idea. My personal opinion is that more than half of the patents granted should not be due to inadequate research to find prior art. Or as my dad says, "Everything old is new again".

    Cheers,

    --
    CutOnce
     
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