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#51
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The Impossibility of Flying Heavy Aircraft Without Training
Immanuel Goldstein wrote: On 2/22/2006 6:40 AM, Thomas Borchert enscribed: Immanuel, Complete text: http://physics911.net/sagadevan.htm Hilarious site. "Scientific panel", my a**. You guys need to get in touch with the chemtrail people. I am not part of a "group", so why the reference to "you guys"? -- Oh yes you are. You are a member, even if you don't carryi the card, of that ever growing group known as "Net Kooks" Harry K |
#52
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The Impossibility of Flying Heavy Aircraft Without Training
Richard Lamb wrote in
ink.net: TRUTH wrote: Richard Lamb wrote in nk.net: Snipped out the relevant discussion part But those statements do not apply to controlled demolitions at the WTC What made you think that this is rec.WTC.collapse.conspiracy.for.clueless. ragheads.that.dont.yet.understand.the.mechanics.of .a.bicycle? Hells bells, boy. We have to start your technical education SOMEwhere. I thought Bernoulli would be a relevant beginning point. LOTS of hot air, but no lift... Richard Don't understand that at all. Perhaps if you used scientific evidence.... |
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The Impossibility of Flying Heavy Aircraft Without Training
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#54
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The Impossibility of Flying Heavy Aircraft Without Training
"C.D.Damron" wrote in message news:G4aLf.784488$x96.666160@attbi_s72... " Anyone here familiar with the Bush family/ Nazi connection??? Maybe someone can make a Flash animation about it I'm not totally conversant with the hows and whys but I understand that there is a certain connection between the Nazis and The Bush, Kennedy, and Lindburgh families. Lindburgh however, at least partially redeemed himself, helping P-38 units in the Pacific greatly extend their planes ranges, increasing our air dominance. In addition, as a civilian consultant/advisor he also shot down a Jap fighter.(The Army then immediately shipped him home) Younger members of the other two families also served honorably and meritoriously in WWII. I'm pretty sure the Bush and Kennedys trying to garner Marks during the 30s may have changed their minds in the early 40s, if not for patriotic reason, perhaps for public relations concerns. Harold |
#55
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The Impossibility of Flying Heavy Aircraft Without Training
"Richard Lamb" wrote in message ink.net... kd5sak wrote: "Richard Lamb" wrote in message nk.net... TRUTH wrote: "Jim Macklin" wrote in news:uX8Lf.104268$4l5.39451@dukeread05: Bernoulli theory: So how do these equations relate to our two-dimensional airfoil? Look again at the Clark Y and notice that an airfoil is a curved shape. While the bottom is relatively flat, the top surface is thicker and more curved. Thus, when air passes over an airfoil, that flow over the top is squeezed into a smaller area than that airflow passing the lower surface. The Continuity equation tells us that a flow squeezed into a smaller area must go faster, and the Bernoulli equation tells us that when a flow moves faster, it creates a lower pressure. I don't quite understand the "squeezed into a smaller area". I Understood that the flow over the top surface had to travel further (thus faster) over the longer curved distance to get from the leading edge to the back of the airfoil. I am just a lay person and do not even play an aeronautical engineer on TV so I may be totally mistaken. Harold I go ya one better, Harold. The AIR isn't even moving! So how does it FLOW anywhere? Richard I was aware that the airfoil was moving thru approximately stationary air, think of it as virtual flow. Then there is the complication brought to the question by that portion of the wing that gets both virtual air flow and the actual airflow provided by propwash. I've already stated my lack of credentials re these questions, I just like sitting in the virtual flow of information(G) Harold |
#56
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The Impossibility of Flying Heavy Aircraft Without Training
Richard Lamb wrote:
"How does a wing generate lift?" Actually they don't. Aircraft only fly because everyone believes they do. Once enough people start doubting they will cease to do so. This is my conspiracy theory and I'm sticking to it. Dan, U.S. Air Force, retired |
#57
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lift, wings, and Bernuolli
So how do these equations relate to our two-dimensional airfoil? Look
again at the Clark Y and notice that an airfoil is a curved shape. While the bottom is relatively flat, the top surface is thicker and more curved. Thus, when air passes over an airfoil, that flow over the top is squeezed into a smaller area than that airflow passing the lower surface. The Continuity equation tells us that a flow squeezed into a smaller area must go faster, and the Bernoulli equation tells us that when a flow moves faster, it creates a lower pressure. I don't quite understand the "squeezed into a smaller area". I Understood that the flow over the top surface had to travel further (thus faster) over the longer curved distance to get from the leading edge to the back of the airfoil. I am just a lay person and do not even play an aeronautical engineer on TV so I may be totally mistaken. The "squeezed into a smaller area" part comes from the classic example of the effect in a venturi. If a (compressible) fluid flows from a fat tube into a thin tube and back into a fat tube, it is being "squeezed into a smaller area" when it's in the thin tube. The pressure in the thin tube is lower. As for the wing, a lot is left out of the explanation. Not all things are equal, and you need to take that into account. For example, although the path over the top is longer, at the end, the air is not put back the way it was prior to passage. The air molecules are moving downards. This is required by the way the trailing edge of the wing is angled. It didn't start out that way, therefore force must be applied to the molecules to make this happen. This can only come from the wing, and that's what holds the wing up. Symmetric airfoils generate lift too if they are at the proper angle of attack. Thin symmetric airfoils generate lift, but the path over the top and bottom is then nearly equal in length. Hollow airfoils (think just the top surface of the wing, with the bottom surface and some of the leading edge removed) will also hold a plane up, and the path over the top and bottom is identical. What is different (before and after) in all cases is that the air has acquired a downward velocity, and this has to be balanced by an upward force applied by the air to the wing. Jose -- Money: what you need when you run out of brains. for Email, make the obvious change in the address. |
#58
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The Impossibility of Flying Heavy Aircraft Without Training
Dan wrote:
Richard Lamb wrote: "How does a wing generate lift?" Actually they don't. Aircraft only fly because everyone believes they do. Once enough people start doubting they will cease to do so. This is my conspiracy theory and I'm sticking to it. Dan, U.S. Air Force, retired Oh My! I don't think we are in Kansas anymore, Toto. I believe! I believe! I believe! (klicking the heels of my ruby red sneakers) |
#59
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The Impossibility of Flying Heavy Aircraft Without Training
kd5sak wrote: "Richard Lamb" wrote in message nk.net... TRUTH wrote: "Jim Macklin" wrote in news:uX8Lf.104268$4l5.39451@dukeread05: Bernoulli theory: So how do these equations relate to our two-dimensional airfoil? Look again at the Clark Y and notice that an airfoil is a curved shape. While the bottom is relatively flat, the top surface is thicker and more curved. Thus, when air passes over an airfoil, that flow over the top is squeezed into a smaller area than that airflow passing the lower surface. The Continuity equation tells us that a flow squeezed into a smaller area must go faster, and the Bernoulli equation tells us that when a flow moves faster, it creates a lower pressure. I don't quite understand the "squeezed into a smaller area". I Understood that the flow over the top surface had to travel further (thus faster) over the longer curved distance to get from the leading edge to the back of the airfoil. I am just a lay person and do not even play an aeronautical engineer on TV so I may be totally mistaken. You are, but don't feel bad. It is a common misconception even still taught by some flight instructors. The truth is, there is nothing connecting molecules of air together. It does not matter that a molecule above the wing has to travel farther in order to 'catch up' to one below the wing. It never met the lower molecule and cares nothing about it. :-) Airplane wings use the curved upper surface to displace air which, because it is slightly sticky, follows the surface of the wing. If you hold a water glass sideways under a stream of water you will see the water curve around the glass all the way to the bottom. Air flowing over a wing does the same thing. As you probably learned in basic physics, though, gases like air maintain a constant total pressure. Air is being accelerated in one direction over the wing, so pressure is being increased in a single direction. We call this dynamic pressure. It is the pressure you feel when you blow on your hand. If dynamic pressure in one direction is increased and total pressure must remain constant, then the pressure in all other directions must be decreased. We call the molecules moving in all these other directions the static pressure. It is like cars in a parking lot, all moving in different directions. If most of them reach a road and start moving in a single direction, then there must be fewer cars moving in other directions. Since most of the air particles are being accelerated in a single direction then there must be fewer of them moving in any other direction. This creates an area of low pressure above the wing. Air above the wing moves into this low pressure area and is in turn accelerated behind and down off the trailing edge of the wing. Newtonian physics tell us that if there is acceleration in one direction there must be an equal and opposite reaction in the other. We call that lift. The amount of lift generated is computed by an equation involving the air density, speed of the wing, area of the wing, and something called the lift coefficient which is basically how much air can be displaced by the wing. Thus, wings generate lift by accelerating air over the top of the wing and then down off the trailing edge. People don't realize it does this because they see pictures of air streams taken in wind tunnels, where the fan continues to blow the air straight backward behind the wing. In actual flight, however, the wing is simply forcing a huge volume of air straight down. You can see this when an airplane flies low over water; the ripples in the water are almost directly below the airplane. Really, a wing is just a big fan blade, only instead of spinning around it moves in a straight line. You do not stand at the edge of the fan to catch the breeze it generates. You stand behind it. You also know that the air blown by a fan comes from in front of the fan. You can hold strips of paper in front of a fan and watch them being sucked toward the fan. Well, the wing is just a fan blade. A great big fan blade, to be sure, but that is all that it is. We call it Bernoulli's principle because Bernoulli was the first to notice that if you accelerate a fluid in one direction that pressure in the other directions is reduced. One method of accelerating a fluid is to force it through a tube that narrows, which is what Bernoulli did. Wings do not really do that, although you commonly see science popularizers showing air flowing through a Bernoulli tube and then removing half the tube and calling it a wing. The fact is, air is not really being compressed in that way at all. It is simply being accelerated over the top of the wing by the front part of the curved surface. That is why lift is greatest at the point where the wing is thickest. Nevertheless, Bernoulli's equations work well for predicting lift even though the method of accelerating the air is slightly different than forcing it through a narrow tube. It is the same principle, just differently implemented. The Wright Brothers actually found that wings generate somewhat more lift than would have been first predicted by Bernoulli. Their first wings were too thick with a greatly exaggerated curve in order to generate maximum lift. What they discovered through trial and error, though, was that although such a wing generated a great deal of lift it also could not generate more by increasing the angle of attack -- the angle with which it meets the air. Instead, what they got by increasing angle of attack was complete separation of air flow from the wing and lift went to 0, what we call a stall. This is one reason the Wrights never rebuilt the first Flyer after it was destroyed shortly after making its first flights. They realized that the machine would never be able to climb very rapidly and that it would always be prone to suddenly falling out of the sky because of stalls. They considered the thing to be extremely dangerous and went back to the drawing board. Also, of course, they destroyed it to keep it out of the hands of potential competitors like Curtis. A shame, really. Or, you can just take the simple explanation and say that the air has to travel further over the wing in order to generate lift. It is wrong, but it works well enough for laymen. |
#60
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The Impossibility of Flying Heavy Aircraft Without Training
Dan wrote in news:ICaLf.19925$Ug4.16290@dukeread12:
Richard Lamb wrote: "How does a wing generate lift?" Actually they don't. Aircraft only fly because everyone believes they do. Once enough people start doubting they will cease to do so. This is my conspiracy theory and I'm sticking to it. Dan, U.S. Air Force, retired Dan, what do you thing of Dr Robert Bowman? He's a retired USAF Lt. Col. and Nasa rocket scientist. He says if NORAD were left alone to do their job, all four planes would have been intercepted. He can be seen in this video, about halfway through: http://www.911busters.com/DC_Truth/index.html Bowman is also running for Congress http://www.rmbowman.com/ |
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