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#71
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Backwash Causes Lift?
"Dudley Henriques" wrote in message
... Tina wrote: Then there's the Mx medical advice column, physics advice -- I'm waiting for a unified field theory, or maybe a proposed standard of care for depression. I had a thought for what would be the longest thread ever in this newsgroup -- "The collected corrections of Mx statements". Bertie could be its editor, he has a deft and gentle way of pointing out errors. I love Bertie's personal rendition of Occam's Razor to Anthony's long extended posts where he "explains" everything in intimate and minute detail. "Nope"! -- Dudley Henriques I'd like to see what his thoughts are on String Theory. LOL. Crash Lander -- Straight and Level Down Under. http://www.straightandleveldownunder.net/ |
#72
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Backwash Causes Lift?
Crash Lander wrote:
"Dudley Henriques" wrote in message ... Tina wrote: Then there's the Mx medical advice column, physics advice -- I'm waiting for a unified field theory, or maybe a proposed standard of care for depression. I had a thought for what would be the longest thread ever in this newsgroup -- "The collected corrections of Mx statements". Bertie could be its editor, he has a deft and gentle way of pointing out errors. I love Bertie's personal rendition of Occam's Razor to Anthony's long extended posts where he "explains" everything in intimate and minute detail. "Nope"! -- Dudley Henriques I'd like to see what his thoughts are on String Theory. LOL. Crash Lander I'm sure he'd most likely say that twine was better :-)) -- Dudley Henriques |
#73
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Backwash Causes Lift?
On Oct 3, 6:33 pm, "Morgans" wrote:
It goes something like this. An airplane is about to takeoff on a runway, that is really a treadmill; a very expensive treadmill. The treadmill senses the airplane's speed, and matches the aircraft's speed, with speed increases of its own. Can the airplane takeoff? Why or why not? I forgot one important qualifier of the treadmill's operation. It goes in the opposite direction of the intended direction of travel for the airplane. Tricky question. I will take a stab at it. You said "sense the airplanes speed". Relative to what? Assuming no friction between wheels and treadmill, the prop of the plane will cause the airplane to move in the wind. The speed "sensing" of the airplane by the treadmill does not really make sense and less you mean that the treadmill senses relative to the wind. If the treadmill senses that the plane has a relative wind speed of Vpw, and starts moving in the opposite direction, and the relative speed of wind against treadwill were nil before all this started, then the treadmill will only cause the wheels to turn twice as fast as they would have if the treadmill had not been moving. In this case, the speed of the plane relative to the treadmill will simply be twice the speed of the plane relative to the win, in opposite direction, of course. The plane will take off. If you mean to imply that there is some way for the treadmill to sense the speed of the plane relative to the treadmill, then adjust the speed of treadmill accordingly, of course, that won't work, as it is a circuitous proposition. -Le Chaud Lapin- |
#74
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Backwash Causes Lift?
"Bertie the Bunyip" ... On 3 Oct, 13:27, "BDS" wrote: "Mxsmanic" wrote Le Chaud Lapin writes: What is the definition of a stall anyway? An abrupt loss of lift. Son, for someone who continually chastises the pilots here for their lack of knowledge, you sure can come up with some doozies yourself! Actually, it's correct, but only because he read it off wickepedia or something. Here's my take on it - a stall occurs at the angle of attack where the coefficient of lift stops increasing with angle of attack and begins to decrease. It continues to decrease beyond this point as angle of attack is increased further. It is not necessarily an abrupt change - most lift versus angle of attack curves that I've seen do not have a drastic (abrupt) drop beyond the peak. BDS |
#75
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Backwash Causes Lift?
BDS wrote: "Bertie the Bunyip" ... On 3 Oct, 13:27, "BDS" wrote: "Mxsmanic" wrote Le Chaud Lapin writes: What is the definition of a stall anyway? An abrupt loss of lift. Son, for someone who continually chastises the pilots here for their lack of knowledge, you sure can come up with some doozies yourself! Actually, it's correct, but only because he read it off wickepedia or something. Here's my take on it - a stall occurs at the angle of attack where the coefficient of lift stops increasing with angle of attack and begins to decrease. It continues to decrease beyond this point as angle of attack is increased further. It is not necessarily an abrupt change - most lift versus angle of attack curves that I've seen do not have a drastic (abrupt) drop beyond the peak. Yes, sorry, you´re right and that´s more accurate. i mistakenly assumed that you were adfvocating the buffet definition. Bertie |
#76
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Backwash Causes Lift?
Le Chaud Lapin wrote: On Oct 3, 4:14 pm, Bertie the Bunyip wrote: Whoowh! Zero point energy! Surely, you must be joking. The exposition I wrote above is nothing more than high school physics. Where do you see me implying zero point energy? I know my physics. Do you? There is no "zero point" energy. Actually, there is. Not theory anymore, proven in a lab.. You´re proving to be quite the plaything. Plain and simple: If a person sucks on a straw, the reason the fluid rises has *NOTHING* to do with Bernoull's principle. It has to do with the balance in force being eliminated. In particular, the air in the straw is removed, so the 14.4lbs/square in will lift the fluid in the straw. This should be familiar to you, since you are a pilot. Where do you think 29.92 Hg comes from? It comes from the height that a column of mercury will rise in a complete rarefied tube in STP, which just happens to be 29.92. Both you and Mxmanic are wrong. Maybe, but I can fly. Bertie |
#77
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Backwash Causes Lift?
Morgans wrote: "Bertie the Bunyip" wrote He's an idiot, what else does one need to know? And yet so many can not resist posting replies to his posts, either with corrections or witty zingers. I'm starting to think that they are the bigger losers. What we have lost is a good newsgroup. Why can't everyone see that when they reply, he wins. And wins and wins..... Folks, I'll say it _again_. The ONLY way to get rid of a know-nothing, know-it-all, obnoxious troll, is to IGNORE him. ALL of him. EVERY time, not just when you feel like it. I thought we were turning a corner a couple days ago, with very few replies to him being posted. Guess again. It´s the main reason I´m here. Bertie |
#78
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Backwash Causes Lift?
In fact, if there is a downward component of the air's velocity that
had come from its passage over the upper surface of the airfoil, then there had been an acceleration provided to that air -- acceleration in this case being conventionally defined as the second time derivative of position. Now, if the air is accelerated downward, and it has mass, it means there had been a force applied. The local prime mover is of course the wing, so it must experience an upward force. Maybe you have a different idea as to on what that equal and opposite force is operating on -- I'd be interested in hearing about that. There are a number of basic principles in operation here, be careful not to paint yourself into too tight a corner unless you are quite expert. I am not claiming skill in this area -- physics was a minor a long time ago -- but I remember some of the basics. |
#79
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Backwash Causes Lift?
Morgans wrote: "Bertie the Bunyip" wrote He's an idiot, what else does one need to know? And yet so many can not resist posting replies to his posts, either with corrections or witty zingers. I'm starting to think that they are the bigger losers. What we have lost is a good newsgroup. Why can't everyone see that when they reply, he wins. And wins and wins..... Folks, I'll say it _again_. The ONLY way to get rid of a know-nothing, know-it-all, obnoxious troll, is to IGNORE him. ALL of him. EVERY time, not just when you feel like it. I thought we were turning a corner a couple days ago, with very few replies to him being posted. Guess again. It´s the main reason I´m here. Bertie |
#80
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Backwash Causes Lift?
Morgans wrote: "Bertie the Bunyip" wrote He's an idiot, what else does one need to know? And yet so many can not resist posting replies to his posts, either with corrections or witty zingers. I'm starting to think that they are the bigger losers. What we have lost is a good newsgroup. Why can't everyone see that when they reply, he wins. And wins and wins..... Folks, I'll say it _again_. The ONLY way to get rid of a know-nothing, know-it-all, obnoxious troll, is to IGNORE him. ALL of him. EVERY time, not just when you feel like it. I thought we were turning a corner a couple days ago, with very few replies to him being posted. Guess again. It´s the main reason I´m here. Bertie |
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