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On Oct 9, 6:15 pm, Ray Vickson wrote:
Heh. I know the argument. I think it's broken out here (sci.physics) many times. (a) It's the Bernoulli effect due to the shape of the wing cross-section, the way we were all taught as kids. (b) No, it's just the angle of attack. Probably true, in large part anyway. Just consider that aerobatics pilots can fly their planes upside-down over considerable distances. If Bernoulli were the sole factor this couldn't happen. R.G. Vickson It doesn't have to be either-or. Both Bernoulli and angle of attack are at work in generating lift. Both the top and bottom surfaces of the wing contribute. The fact that aerobatic planes can be flown upside down shows that if you take a normal airfoil and fly it upside down at the right angle of attack, it will still generate lift. But unless it has a symmetric airfoil, it will be a lot less efficient when it is operated upside down. This is because the when it is upside down, the top surface of the wing is flat rather than curved, and hence you lose a lot of the lift which this surface generates when it is rightside up. This is why many aerobatic planes have symmetric airfoils. A symmetric airfoil works well upside down because it still has a curved surface on top to help generate lift. |
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Phil wrote in news:1192037923.115677.275220
@o3g2000hsb.googlegroups.com: On Oct 9, 6:15 pm, Ray Vickson wrote: Heh. I know the argument. I think it's broken out here (sci.physics) many times. (a) It's the Bernoulli effect due to the shape of the wing cross-section, the way we were all taught as kids. (b) No, it's just the angle of attack. Probably true, in large part anyway. Just consider that aerobatics pilots can fly their planes upside-down over considerable distances. If Bernoulli were the sole factor this couldn't happen. R.G. Vickson It doesn't have to be either-or. Both Bernoulli and angle of attack are at work in generating lift. That's right, but what's more is that Bernoulli is strengthened by angle of attack and it's that which provides most of the increase n lift at higher angles. Even with a flat bottom wing being flown inverted, most of the lift is still coming from Bernoulli. Bertie |
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If you will be satisfied with empirical evidence, stick your hand out
the window of the car while going 50-60 MPH. Experiment with different angles of attack. You will no doubt experience lift when your hand has a positive angle of attack. Poor man's wind tunnel - but illustrates that just about anything relatively flat will fly given enough speed and a positive angle of attack. David Johnson |
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On 28 Okt, 05:39, Dave wrote:
If you will be satisfied with empirical evidence, stick your hand out the window of the car while going 50-60 MPH. Experiment with different angles of attack. You will no doubt experienceliftwhen your hand has a positive angle of attack. Poor man's wind tunnel - but illustrates that just about anything relatively flat will fly given enough speed and a positive angle of attack. David Johnson The problem is probably, that Bertie does have a car, so the simple experiment is not possible for him. He might find a bus, where he can open the window and try. The risk is that he does not understand the physical effects on his hand. Since he does not understand how to see the vertical airflow from the wings at AOA in this picture, he has a big problem: http://www.efluids.com/efluids/galle...s/Morris_4.jsp |
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jon wrote in news:1193570966.513645.238920
@o38g2000hse.googlegroups.com: On 28 Okt, 05:39, Dave wrote: If you will be satisfied with empirical evidence, stick your hand out the window of the car while going 50-60 MPH. Experiment with different angles of attack. You will no doubt experienceliftwhen your hand has a positive angle of attack. Poor man's wind tunnel - but illustrates that just about anything relatively flat will fly given enough speed and a positive angle of attack. David Johnson The problem is probably, that Bertie does have a car, so the simple experiment is not possible for him. Yep, I do have a car. an airplane too. He might find a bus, where he can open the window and try. The risk is that he does not understand the physical effects on his hand. Since he does not understand how to see the vertical airflow from the wings at AOA in this picture, he has a big problem: http://www.efluids.com/efluids/galle...s/Morris_3.jsp Look again, fjukkwit. You have yet to explain th elow on top of the wing.. Bertie |
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![]() "Dave" wrote in message ups.com... If you will be satisfied with empirical evidence, stick your hand out the window of the car while going 50-60 MPH. Experiment with different angles of attack. You will no doubt experience lift when your hand has a positive angle of attack. Poor man's wind tunnel - but illustrates that just about anything relatively flat will fly given enough speed and a positive angle of attack. That's why wings have camber. 'Cause they don't need 'em. Bertie's a shill for the Alcoa Camber Conspiracy. ...they've sold more metal by convincing every successful aircraft designer and manufacturer in the history of aviation that upper camber is necessary, when all they need are two simple deflection plates. Fortunately, the wizards at sci.physics have busted the conspiracy and we all see now how the designers of all aircraft were grievously wrong. -c |
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"Gatt" wrote in
: "Dave" wrote in message ups.com... If you will be satisfied with empirical evidence, stick your hand out the window of the car while going 50-60 MPH. Experiment with different angles of attack. You will no doubt experience lift when your hand has a positive angle of attack. Poor man's wind tunnel - but illustrates that just about anything relatively flat will fly given enough speed and a positive angle of attack. That's why wings have camber. 'Cause they don't need 'em. Bertie's a shill for the Alcoa Camber Conspiracy. ...they've sold more metal by convincing every successful aircraft designer and manufacturer in the history of aviation that upper camber is necessary, when all they need are two simple deflection plates. Yeah, that's it. Also, I get good money from the guys who deice aircraft upper surfaces.. Fortunately, the wizards at sci.physics have busted the conspiracy and we all see now how the designers of all aircraft were grievously wrong. It had to end for me sometime. ;( Well, I had a good run.. Bertie |
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Le Chaud Lapin wrote:
I am trying to convince them that, if there is air on the inside of the wing, it pushes against all sides of the inside of the wing, including both top underside and bottom overside, and thereby nullifying any effect it would have on the wing. You are trying to convince one person - there is no plural. Just for the record, I pointed the OP at the following NASA web pages and after first thanking me, has decided NASA's explanation is somehow suspect: http://www.grc.nasa.gov/WWW/K-12/airplane/lift1.html http://www.grc.nasa.gov/WWW/K-12/airplane/right2.html http://www.grc.nasa.gov/WWW/K-12/airplane/downwash.html Note follow-ups set to sci.physics only. |
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![]() "Le Chaud Lapin" wrote in message ps.com... I am an electrical engineer with experience in analag That would be "analog" there, wouldn't it, engineer? Now, think about how "attention to detail" applies to math. I count 8-9 people in the group who are utterly convinced that I am inept at physics, mathematics, etc. Nobody's saying you're inept at anything; just arrogant about your assumptions, and wrong, and quite possibly dishonest about your identity. Taking on the science of NASA, for example, challenges the kind of people who put men on the moon, shuttle aircraft into space and back, and robots on Mars. What I'm saying is, they've proven their ability to do math and physics. You're talking about two pieces of paper on a table or whatever, admitting you don't fully understand aerodynamics, and then challenging the kind of people who did research using SR-71 blackbirds and spacecraft. ....in a pilots' forum. What in hell kind of response did you possibly expect? -c |
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On Oct 9, 4:29 pm, "Gatt" wrote:
"Le Chaud Lapin" wrote in glegroups.com... Taking on the science of NASA, for example, challenges the kind of people who put men on the moon, shuttle aircraft into space and back, and robots on Mars. What I'm saying is, they've proven their ability to do math and physics. You're talking about two pieces of paper on a table or whatever, admitting you don't fully understand aerodynamics, and then challenging the kind of people who did research using SR-71 blackbirds and spacecraft. My initial assertion was that the experts were not in agreement about causes lift. Many posters said that I was wrong, that there was total agreement, that I was mistaken. ...in a pilots' forum. What in hell kind of response did you possibly expect? A little bit more focus on the physics, a loss less focus on the poster. And with regard to the demonstration I presented in my original post, I was expecting at least one pilot to give a correct explanation why the lower paper is lifted off the ground, and not only has anyone given a correct explanation, but no one has given any explanation at all. -Le Chaud Lapin- |
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