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  1. #183
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    Oustanding post, Hearthman!

    I figure you might enjoy the following since you say you haven't seen anything from the scientific community on it. MIT's Thomas Eagar had this to say about the fires (from one of the articles I posted early on);

    The fire is the most misunderstood part of the WTC collapse. Even today, the media report (and many scientists believe) that the steel melted. It is argued that the jet fuel burns very hot, especially with so much fuel present. This is not true.

    Part of the problem is that people (including engineers) often confuse temperature and heat. While they are related, they are not the same. Thermodynamically, the heat contained in a material is related to the temperature through the heat capacity and the density (or mass). Temperature is defined as an intensive property, meaning that it does not vary with the quantity of material, while the heat is an extensive property, which does vary with the amount of material. One way to distinguish the two is to note that if a second log is added to the fireplace, the temperature does not double; it stays roughly the same, but the size of the fire or the length of time the fire burns, or a combination of the two, doubles. Thus, the fact that there were 90,000 L of jet fuel on a few floors of the WTC does not mean that this was an unusually hot fire. The temperature of the fire at the WTC was not unusual, and it was most definitely not capable of melting steel.

    In combustion science, there are three basic types of flames, namely, a jet burner, a pre-mixed flame, and a diffuse flame. A jet burner generally involves mixing the fuel and the oxidant in nearly stoichiometric proportions and igniting the mixture in a constant-volume chamber. Since the combustion products cannot expand in the constant-volume chamber, they exit the chamber as a very high velocity, fully combusted, jet. This is what occurs in a jet engine, and this is the flame type that generates the most intense heat.

    In a pre-mixed flame, the same nearly stoichiometric mixture is ignited as it exits a nozzle, under constant pressure conditions. It does not attain the flame velocities of a jet burner. An oxyacetylene torch or a Bunsen burner is a pre-mixed flame.

    In a diffuse flame, the fuel and the oxidant are not mixed before ignition, but flow together in an uncontrolled manner and combust when the fuel/oxidant ratios reach values within the flammable range. A fireplace flame is a diffuse flame burning in air, as was the WTC fire.

    Diffuse flames generate the lowest heat intensities of the three flame types.

    If the fuel and the oxidant start at ambient temperature, a maximum flame temperature can be defined. For carbon burning in pure oxygen, the maximum is 3,200°C; for hydrogen it is 2,750°C. Thus, for virtually any hydrocarbons, the maximum flame temperature, starting at ambient temperature and using pure oxygen, is approximately 3,000°C.

    This maximum flame temperature is reduced by two-thirds if air is used rather than pure oxygen. The reason is that every molecule of oxygen releases the heat of formation of a molecule of carbon monoxide and a molecule of water. If pure oxygen is used, this heat only needs to heat two molecules (carbon monoxide and water), while with air, these two molecules must be heated plus four molecules of nitrogen. Thus, burning hydrocarbons in air produces only one-third the temperature increase as burning in pure oxygen because three times as many molecules must be heated when air is used. The maximum flame temperature increase for burning hydrocarbons (jet fuel) in air is, thus, about 1,000°C—hardly sufficient to melt steel at 1,500°C.

    But it is very difficult to reach this maximum temperature with a diffuse flame. There is nothing to ensure that the fuel and air in a diffuse flame are mixed in the best ratio. Typically, diffuse flames are fuel rich, meaning that the excess fuel molecules, which are unburned, must also be heated. It is known that most diffuse fires are fuel rich because blowing on a campfire or using a blacksmith’s bellows increases the rate of combustion by adding more oxygen. This fuel-rich diffuse flame can drop the temperature by up to a factor of two again. This is why the temperatures in a residential fire are usually in the 500°C to 650°C range.2,3 It is known that the WTC fire was a fuel-rich, diffuse flame as evidenced by the copious black smoke. Soot is generated by incompletely burned fuel; hence, the WTC fire was fuel rich—hardly surprising with 90,000 L of jet fuel available. Factors such as flame volume and quantity of soot decrease the radiative heat loss in the fire, moving the temperature closer to the maximum of 1,000°C. However, it is highly unlikely that the steel at the WTC experienced temperatures above the 750–800°C range. All reports that the steel melted at 1,500°C are using imprecise terminology at best.

    Some reports suggest that the aluminum from the aircraft ignited, creating very high temperatures. While it is possible to ignite aluminum under special conditions, such conditions are not commonly attained in a hydrocarbon-based diffuse flame. In addition, the flame would be white hot, like a giant sparkler. There was no evidence of such aluminum ignition, which would have been visible even through the dense soot.

    It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

    The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.
    Last edited by scrogdog; 10-02-2012 at 09:53 AM.
    "Social networking" is an oxymoron.

  2. #184
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    There is another detail GA has not come to peace with...

    When a member of the military is killed protecting his/her country... they get a pittance... not even enough to bury them... however:

    When 911 happened, every family got upwards of $250K... and we never heard much from them. Sounds like buy-off $$$ to me.

    And as usual... the media does not investigate.

    Too many fishy things wit no explanation... or an explanation a grade-schooler would see through.

    The public is not looking... therefore they do not see.
    GA-HVAC-Tech

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  3. #185
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    I agree with you on that one.

    Victims families recieved over 38 billion dollars; a large portion was from insurance companies but 42% was from the Feds.

    Ostensibly, first the families had to sign an agreement not to sue the airlines. The Fed story is that the move was to protect them (the airlines) and the economy.

    To me, it makes no more sense than openly telling Mexicans to come to America and taxpayers will feed them.

    That the feds mishandle our money in countless ways on a daily basis is, I think, not in question.

    And neither Romney or Obama will fix that, I assure you.
    "Social networking" is an oxymoron.

  4. #186
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    Quote Originally Posted by scrogdog View Post
    I agree with you on that one.

    Victims families recieved over 38 billion dollars; a large portion was from insurance companies but 42% was from the Feds.

    Ostensibly, first the families had to sign an agreement not to sue the airlines. The Fed story is that the move was to protect them (the airlines) and the economy.

    To me, it makes no more sense than openly telling Mexicans to come to America and taxpayers will feed them.

    That the feds mishandle our money in countless ways on a daily basis is, I think, not in question.

    And neither Romney or Obama will fix that, I assure you.
    Seems to me the American public does not have the gonads to elect someone that would ask some HARD questions and demand answers... In GA's opinion a sign the American public has the govt they deserve.

    Just a side note... I did not see a single candidate on the GOP debates I think would ask the hard questions and demand answers...
    Now I suspect we will see some real fantasy with supporters of their fringe candidates saying different... <grin>

    To add a thought... Seems to me (yes, me), when I watch media types answering questions from the audience (even the so called investigative ones... thinking of John Stossel here), they are VERY careful to follow a company line and NOT say anything even remotely questionable. Almost like they have dual agendas... Anyone else notice this?
    Last edited by ga-hvac-tech; 10-02-2012 at 09:59 AM. Reason: Added thought
    GA-HVAC-Tech

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  5. #187
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    Quote Originally Posted by scrogdog View Post
    What I don't get is why both you and GA consider the matter closed.
    This case is closed without something new to examine like the debris, which will never surface. You seem to infer that science is above public scrutiny. Public opinion has closed this case far more than the findings have. As Liberty said, science can say what may have brought WTC7 down but without the raw materials to examine, it has a hint of speculation attached to it.

    Where was the scientific community when the Warren Commission offered their take on the JFK assassination? Why didn’t they tell us that Kennedy’s brain could only blow out the back of his head if he was shot from the front? Seems like a fact that 1.7 millions scientists would agree on.

    Many scientists are funded by grants and they are often the last to ruffle feathers. Besides there are too many Americans that do not want to know the truth…if that is where the truth leads. There are too many that think like you - that science is to be completely trusted and that nobody in this country would or could pull this off. So, case closed.
    Last edited by Brian GC; 10-02-2012 at 11:42 AM. Reason: typo

  6. #188
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    Fifteen hundred scientists are opposing the “white paper” findings of 911 and look what is happening to them. They are being publicly tarred and feathered as kooks. So how many others agree with them but do not want to join their group only to be ridiculed and jeopardize their careers? Scientists are not above public ridicule as you infer.

  7. #189
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    Did you read the actual article?

    That was NOT speculation. Niether was any of the science that I posted.

    For one simple reason, no "evidence" can change the way that the laws of physics works or how combustion science works. So, you are wrong. Debris, no matter what it is, will NOT demonstrate that the laws that govern this universe have all of a sudden changed.

    If you'll actually read something for once, you'll see that even the color and thickness of the smoke tells us WHAT THE FIRE WAS. The photos of the columns IN THREES (meaning they were support) showed no sign of melting whatsoever. CTers photos of molten metal do not actually show molten metal. For example, this one...



    Do you understand what MOLTEN means? Obviously Dr. Wood does not. How could such a highly credentialed (in dentistry, as far as I can tell in investigating your team so far. All of two civil engineers) person make such a mistake?

    Note that the fact that her specialty is dentistry does not make her wrong, but does go a long way in explaining her interpretation of things.

    We spoke earlier about the bias of mankind. Like the guy from South Korea who said he cloned humans but was exposed as a glory grabbing liar. Again, this is the PRECISE reason why there are rules and standards. To help us weed out the charlatans.

    It appears we could say the same about Susan Wood, who if, by the way, was any sort of physics person, or even a pool player, would clearly understand that her billiard ball example fails to take in to account a fairly simple concept in science; the transfer of momentum. You could not play the game of billiards without it.

    Do I need to examine the billiard ball to know this? No. Similarly, science has no need of the debris. We discover what happened in multiple other ways that you clearly don't undertand, even when someone tries to explain them to you.

    Tell me Brian, how many of these "experts" had you heard of before this supposed controversy?

    So, what's your judgement on Susan Wood? Over her head? Unprincincipled liar? Downright fool? Glory grabbing moron?

    Again, debris is irrelevent. If public opinion has given up, that doesn't mean that science has.
    "Social networking" is an oxymoron.

  8. #190
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    Quote Originally Posted by Brian GC View Post
    Fifteen hundred scientists are opposing the “white paper” findings of 911 and look what is happening to them. They are being publicly tarred and feathered as kooks. So how many others agree with them but do not want to join their group only to be ridiculed and jeopardize their careers? Scientists are not above public ridicule as you infer.
    That's sort of the point. The scientists of the world are peer reviewing junk science. And are calling it such.

    Rightly so. What else should we do, Brian?

    Kooks might be going a little far. Clearly unprincipled folks, however.
    "Social networking" is an oxymoron.

  9. #191
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    So where was the scientific community when the Warren Commission told us that a bullet entering the back of Kennedy’s head would cause his brain to blow out the back, not the front? I’ll tell you what they did. They stood down to public pressure.

  10. #192
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    Could be. I wasn't concerned enough about it to check it out, to be honest.

    What might be of more concern to me given the world as it is... is the name of his brother's assassin.

    Sirhan Sirhan.

    Seems things began with the Muslims in the 60's then.

    That has nothing to do with the task at hand.

    So, your opinion of Susan Wood?
    "Social networking" is an oxymoron.

  11. #193
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    Scrog, why do you keep making post after post....cant you say it with one post? Its annoying! quit being an annoyance! damn sheesh!...some peoples kids.
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

  12. #194
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    Quote Originally Posted by coolwhip View Post
    Scrog, why do you keep making post after post....cant you say it with one post? Its annoying! quit being an annoyance! damn sheesh!...some peoples kids.
    No, simply because I refuse to allow the intellectually dishonest technique of attempting to change the subject when one doesn't know where to go next in the face of what was just presented, or is out of ammo, so to speak.

    Concede the point if one likes. But don't debate in that cowardly fashion.

    This topic is about conspiracy theories and has evolved from that to specific ones like potential junk science involving WTC and building 7. If one wishes to discuss some other matter, like science itself, they are welcome to start a new thread and discussion.

    JFK could rightly be considered here, but not exactly what we were just talking about. Otherwise, point and counter-point. That's how debate works.

    At least I'm reviewing YOUR stuff. Who the experts are, what their credentials are, what their claims are. You folks do no such thing. Do you think I just pulled the billiard balls thing out of thin air, or did I observe one of your sources?

    Put that up against CTers FLAT OUT REFUSAL to give the opposition similar consideration. Please find for us ONE SINGLE THING that was responded to with regards to my sources, thier expertise, thier claims.

    You won't find a single instance of that.

    So, clueless about science AND debate. Par for the course with this crowd I suppose. No wonder thier proper forms upset you.

    Perhaps you need a break, CW, as I often take myself.
    "Social networking" is an oxymoron.

  13. #195
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    I got a break when I started this life. You should have seen me in past lives!...you have heard of Plato and Socrates? they were fools compared to me. Some think that it was the Florentine artist Andrea del Verrocchio that taught Devinci how to paint...nope, it was coolwhip!
    God even told me that I could have rivaled Alexander the Great at his best.

    I also tried to tell the Jews at the Sanhedrin trial to pick Jesus, but the idiots chose a criminal instead....nobody listened then, and nobody listens now...mankind will never change.

    Anyway, I digress...carry on.
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

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