The lift tag has no wiki summary.
6
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5answers
2k views
Does it take significantly more fuel to fly a heavier airplane?
I was reading in the papers how some-airline-or-the-other increased their prices for extra luggage, citing increased fuel costs.
Now I'm a bit skeptical. Using the (wrong) Bernoulli-effect ...
14
votes
2answers
4k views
How can airplanes fly upside down?
I've read many times, including here on this very site that the commonly known explanation of flight is wrong, and that airplanes can fly because the shape of their wings deflects air down. This makes ...
0
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2answers
55 views
Are the hypotheses of the Bernoulli equation satisfied for a bird or airplane wing at low Mach number?
A previous question by David Zaslavsky was a request for a broad, "how things work" type of explanation of the lift of an airfoil. The answers given there are enlightening, but don't address a more ...
6
votes
2answers
118 views
Could some design of a propeller be used in both air and water?
Propellers in water are smaller in diameter. They also move more slowly. On the other hand, aircraft propellers are larger in diameter, have narrower blades and operate at very high speeds. An ...
4
votes
5answers
634 views
What principles does an air glider use?
I just saw this video which was kind of nifty. What principles govern this? Is it simply that 700 lbs of air pressure are exerted from that little 1 HP blower? What would you have to take into ...
0
votes
1answer
93 views
Surviving Free Fall with the Help of Mr. Bernoulli
What is the best strategy to survive a free fall naked out of a jetliner at cruising altitude (ignoring temperature)?
For instance, my strategy would be to streamline my fall so that my terminal ...
5
votes
4answers
167 views
Can a balloon be used as an anchor point for a pulley?
For a physics/ engineering contest, I want to use a large balloon as an anchor point for a pulley. This would allow me to raise and drop masses.
However, in testing, when I pull on the pulley the ...
0
votes
2answers
189 views
Forces on an aircraft - thrust, lift, drag, weight
I'm extremely sceptical about the wikipedia page on aircraft flight mechanics. When describing 'straight climbing flight', it says:
lift is unable to alter the aircraft's potential energy or ...
3
votes
3answers
270 views
Does launching a rocket in lower density air require more or less fuel?
Given two environments that are identical, except for air density (e.g. Cape Canaveral, but at Mount Everest's height), would launching a rocket require more or less fuel at the lower air density?
1
vote
1answer
321 views
How much lift does the average latex helium filled party balloon produce?
How much lift does the average helium filled party balloon produce? (not including any extras like ribbon string)
1
vote
3answers
66 views
How does the position of lift affect the stability of the lifted object?
Consider this example:
Treat G as 10.
The blue blocks provide lift of 10N, or -1KG.
The red block has a weight of 20N, or 2KG.
The black bar has no weight.
All have their center of gravity in ...
8
votes
2answers
429 views
Does a wing in a potential flow have lift?
I have a hard time understanding whether or not a wing placed in a potential flow, assuming there is no viscosity and no friction with the wing, will produce a lift. I've seen several contradictory ...
11
votes
5answers
444 views
Is flying really easier on smaller scales?
In the book Playing with Planets, the author makes the following argument, pertinent to flying robots of the future:
As it is, an important law of physics says that smaller organisms fly much more ...
12
votes
2answers
582 views
Why don't rockets tip over when they launch?
Rockets separate from the launch pad and supporting structures very early in flight. It seems like they should tip over once that happens.
Why don't they tip over? Is it due to a well designed ...
68
votes
3answers
5k views
What really allows airplanes to fly?
What aerodynamic effects actually contribute to producing the lift on an airplane?
I know there's a common belief that lift comes from the Bernoulli effect, where air moving over the wings is at ...
3
votes
2answers
623 views
How much lift does an airplane get from its wings, vs the rest of the airframe?
Consider a big commercial airliner, like a 727, 747, or a 787.
At cruising altitude, under standard conditions, how much of the lift of the aircraft comes from the wings, and how much from the rest ...
2
votes
2answers
254 views
Forces on an airfoil
I'm building an airplane (Super Baby Great Lakes) and I'm wondering something about airfoils. In particular (this plane is fabric covered), I'm wondering about the lifting forces on the main wings. ...
-2
votes
2answers
154 views
Why does the higher pressure of air underneath an aeroplane wing keep it flying?
With aeroplane flight, the wings are shaped so that the air that goes over the top of the wing has to travel faster than the air that goes below the wing. This means that the air below the wing has ...
5
votes
2answers
539 views
Is it possible to fly like a bird using semi-motorized wings?
On his website http://www.humanbirdwings.net/ the dutch engineer Jarno
Smeets claims to have successfully build a set of 17 m^2 bird-like
wings from material of a kite. It is claimed that it ...
4
votes
4answers
971 views
Why do aircraft inner wings lose lift when turning?
first question here, so please be gentle!
I'm reading an entry-level engineering course book and am currently up to discussion of aircraft design.
There's one particular statement that is unclear to ...
4
votes
1answer
213 views
Do atmospheric physics prevent hot air balloons from ascending over 60,000ft?
I was reading the altitude records for hot air balloons on Wikipedia, and noted that the max hot air balloon altitude was about 60,000ft. It didn't really say if there was a reason why. I know that ...
3
votes
4answers
400 views
Could hydrogen liberated from water provide lifting energy which exceeds the energy it took to liberate it from water
I was thinking about Hydrogen balloons and that large ones which are used for weather balloons which sometimes go up to 100,000 ft (approx 30km). Then I was wondering, how much potential energy has ...
0
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0answers
208 views
Is the Hanging Gardens of Babylon mystery still unresolved? [closed]
I'm wondering if the water lifting secret method of Hanging Gardens of Babylon still unresolved.
I tried to find anything related to it at Google Patent but nothing was there related to it.
Does ...
8
votes
1answer
2k views
Why exactly does a boomerang return back to the thrower?
I was always intrigued by the phenomena that govern the returning back of a boomerang to the thrower.
Even if it is dependent on various factors such as velocity, aerodynamics, wind resistance and ...
