Was Marchaj having us on?

Discussion in 'Hydrodynamics and Aerodynamics' started by Sailor Al, Apr 12, 2021.

?

Did Marchaj know he was wrong when he claimed, on P199 in my post #63, that "A arrives ...before B".

  1. Yes, and therefore he was "having us on".

    100.0%
  2. No, he didn't understand that the air flows faster over the upper surface.

    0 vote(s)
    0.0%
  3. He was right, air flows travels over the respective surfaces at equal speed.

    0 vote(s)
    0.0%
  4. He confused A with B. (The pic shows B arriving at the TE before A!)

    0 vote(s)
    0.0%
Multiple votes are allowed.
  1. Will Gilmore
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    Will Gilmore Senior Member

    But it takes a concensus for the World to believe it recognizes the physical truth. Simply saying something is fact, in the face of an ignorant majority, isn't going to improve anyone's understanding.

    Sailor Al, it sounds more like your objection to this book has less to do with what it says and more to do with how the rest of the world leans on it. Perhaps your disagreement is more with those who cite this work than with the author who was writing about what he believed was the latest and most complete understanding of a natural phenomenon at the time.
     
  2. jehardiman
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    jehardiman Senior Member

    I concur; Physics doesn't give a damn about our varied opinions or consensus.
    Suck it up Al; you, Marchaj, me, everyone...are wrong, wrong, wrong. Al, since you appear to like simple, childlike, physical analogies, think of it as game of Pin the Tail on the Donkey....no one ever get it perfect, but some get closer than others. So from that perspective, IMHO, Marchaj was "having us on" much less than others I could name.
     
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  3. Sailor Al
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    Sailor Al Senior Member

    Are you are seriously offering a Wikipedia page to support your argument?
    You must have missed the process of peer review.
     
  4. Sailor Al
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    Sailor Al Senior Member

    But you do agree that he was "having us on" then?
     
  5. Sailor Al
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    Sailor Al Senior Member

    Not sure that adds to the discussion.
     
  6. Howlandwoodworks
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    Howlandwoodworks Member

    Dear Sailor AI,
    I am not arguing with you.

    Your question was and I am paraphrasing your original question to give him one his Academy titles. (Was Professor Czesław Marchaj having us on?)
    I would say he was "not" to you, all here, and any Surviving Members of His Family.
    He does indeed have a Wikipedia page as well as Academic and Professional Dossiers.
    Yours truly,
    John Howland

    QVI NON INTELLIGENT, AVT TACEAT, AVT DISGAT.
     
    Last edited: Apr 17, 2021
  7. Sailor Al
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    Sailor Al Senior Member

    Nope, not a Professor, according to his bio in the publisher's note on the dust jacket:
     

    Attached Files:

  8. Howlandwoodworks
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    Howlandwoodworks Member

    Czesław Antony Marchaj (9 July 1918 – 21 July 2015), often known in the West as C.A. Marchaj or Tony Marchaj, was a Polish-British yachtsman and professor whose published scientific studies of the aerodynamics and hydrodynamics of sailing boats have been influential on yacht, sail and rig designers. He was the author of "Sailing Theory and Practice" and approximately 60 other publications on sailing. He was a member of the Royal Institute of Naval Architects (RINA),[1] and he was awarded the Silver Medal of The International Sailing Federation (ISAF).[2]


    Early life and educationHis original youth interest and professional career choice was aviation, with emphasis on gliding.[3] After studying at the State Academy of Mechanical and Electrical Engineering[Note 1] in Warsaw, he joined the Warsaw University of Technology. Led wind tunnel testing of combat airplanes.[3] During the German and Soviet occupation of Poland during World War II soldier of the Polish Home Army (Armia Krajowa).[3] Also, during the war years, Czesław Marchaj studied philosophy (clandestinely, as higher education was suppressed by occupation authorities) under Władysław Tatarkiewicz.[4]

    In the postwar years his interest had turned towards sailing. This resulted (in 1949) in a sentence in a politically motivated process to a prison term[Note 2] under false charges of espionage and "trying to escape to the West" and subsequent long term harassment.[3][Note 3]


    Career

    In 1953, drawing on his professional background in aerodynamics, Czeslaw Marchaj designed modifications (within class rules) to his Finn class racing boat and subsequently sailed it to a surprising win in a multiday Warsaw-Gdańsk river regatta. Asked by the Warsaw sailing clubs community about his race performance, he prepared and presented a series of lectures on sail aerodynamics during 1953/54 winter off-season. These lectures had been edited into the first version of the book "Sailing Theory and Practice". This work had been well received and published in Poland and abroad.[Note 4]

    On the strength of "Sailing Theory...", in 1969, Czesław Marchaj was granted a two-year scholarship by the University of Southampton. In 1970 he decided to live in United Kingdom (which was considered defection by Polish authorities and resulted in a long term separation from his family which was barred from leaving Poland to join him).[3] In the years 1969-1990 Czesław Marchaj continued research at University of Southampton[Note 5] and was a visiting lecturer at multiple top ranking academic institutions. At University of Southampton he pioneered wind tunnel testing of (scaled) sailing ships[4] His work included books "Aero-Hydrodynamics of Sailing" (1979), "Seaworthiness: The Forgotten Factor" (1986) and "Sail Performance: Techniques to Maximize Sail Power" (1996). In 1979, after many boats were sunk with a loss of life in the Admirals Cup regatta Fastnet race Czesław Marchaj was commissioned to investigate the problem of dynamic instability of yachts in foul weather.[Note 6] He was also involved in the America's Cup competition bid preparations for the British team.[Note 7]

    His books contain a rigorous theoretical and experimental approach to issues in design and operation of sailing vessels, resulting in detailed analysis, confirmation or debunking of many previously assumed facts in sailing practice.
     
  9. Sailor Al
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    Sailor Al Senior Member

    I think you're just quoting the notoriously unreliable Wikipedia.
    When, and of which University was he appointed Professor?
     
  10. Howlandwoodworks
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    Howlandwoodworks Member

    Sailor AI,
    Thanks for pointing out my mistake.
    Your question was “Was Czesław Marchaj having us on?”
    I would say he was "not" to you, all here, and any Surviving Members of His Family.
    The best luck with all of your endeavours.
     
    Last edited: Apr 17, 2021
  11. jehardiman
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    jehardiman Senior Member

    Absolutely not. He, using previous work, came to an understanding and models of how to solve an engineering problem, and fairly efficiently too. Hundreds of others have also looked at previous work, and came up their own models and solutions. As I have said before, ask three different aero-hydrodynamicists how to calculate a sailing vessel and you will get six or seven different answers. At issue is how accurate is the answer. There are many models that have precision, but not accuracy. And again how accurate does the answer needs to be when when there are so many known unknowns. He, unlike the two threads you have started, didn't waste ink (or bandwidth) "having it on" ripping other's work. He presented his models, what they were derived from, and experimental results, much like Hoerner or Lamb.
    Actually, reading back through your two threads, I'm not sure you've added anything to discussion. Like any trolling charlatan running a ponzi scheme, you hint a deeper knowledge but never offer anything to prove that. Show us the model and the math.
     
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  12. Sailor Al
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    Sailor Al Senior Member

    He was known and Tony Marchaj to all who knew him, and for us in the sailing world there was only one Marchaj, so I think, requiring his unpronounceable (to English speakers) first name to identify him is being a tad pedantic!

    I think I have provided ample evidence that he was, but all you have done is say "no". That's hardly an argument!
    Can we at least agree that his introduction of the rotating cylinder, initiated by Prandtl in 1920 and it's subsequent influence on the Flettner-Rotor add nothing to our understanding about the way an aerofoil force is generated on a sail?
     
  13. DogCavalry
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    DogCavalry I aim to misbehave.

    If you roll in the mud with pigs, you both get dirty, but the pig doesn't mind.
     
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  14. philSweet
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    philSweet Senior Member

    File this under "even a blind dog finds a bone from time to time."

    I had a strong feeling that I had run across that gear metaphor before, and that it was old, like Isaac Newton old.

    [​IMG]

    From the same book I referenced earlier, Arial Flight, 1907, by Lanchester, there is the following discussion. I had to retype it, I couldn't get an image to post. Page 73, section 55, titled "Some Difficulties of Theory" —

    "In all case of skin-friction where the index exceeds 1.5, the motion is accompanied by turbulence, and if the value of the index rises to 2, as it would appear to do approximately in the case of the roughened surface, then the dimensionless equation (as pointed out by Allen) shows that the resistance is independent of viscosity, and the whole of the energy is expended dynamically in producing fluid motion. Under these circumstances, we must understand viscosity as merely acting as gearing [italics original] by which rotation motion is imparted to the fluid, although it is difficult to understand how such a gearing can be continually imparting rotation to new masses of fluid without a certain amount of slip, and such slip would betoken an expenditure of motion in viscous energy and necessitate the value of the index being less than 2."

    The index being discussed is the exponent of velocity in the friction-resistance equation— 1.0 for Stokes flow, 1.5 for Allen flow, and 2.0 for Newtonian flow.
     
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  15. Howlandwoodworks
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    Howlandwoodworks Member

    Sailor AI,
    I am not arguing with you.
    Your question was “Was Marchaj having us on?”
    I would say. “He was not having us on."
    Here is an example of having us on by Kurt Vonnegut, out of his book (A Man Without A Country)
    “It was a big mistake for me to take a degree in anthropology anyway, because I can't stand primitive people — they're so stupid.”

    One more by Kurt
    “Be soft”
     
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