A subset of [tag:fluid-dynamics] concerning primarily forces such as lift and drag generated on bodies as they move through gasses or as gasses move through the body (typically air).
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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 ...
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4answers
808 views
Helicopter in an Elevator
You buy one of those remote control toy helicopters. You bring it into an elevator. The elevator goes up. Does the helicopter hit the floor or does the floor of the elevator push the air up into the ...
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Why does the air flow faster over the top of an airfoil?
I understand the common explanation of lift, which describes the airflow over the top of the wing as moving faster than the air below the wing. However, I don't quite understand why the air moves ...
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3answers
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How is the Joukowsky Transform used to calculate the Flow of an Airfoil?
As I read in The Road to Reality by Roger Penrose, the Joukowsky transform $$w(z) = \frac12\left( z + \frac1z \right)$$
after Nikolai Zhukovsky (transcribed in several versions from Никола́й Его́рович ...
13
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4answers
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Why is exhaling more forceful than inhaling?
By blowing at pencil, a piece of paper, or another object up to fifty centimeters away, I can cause it to move away from me significantly. But I can't move an object toward myself by inhaling sharply ...
8
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1answer
388 views
NASCAR drafting at Daytona
This year, the racetrack at Daytona has been repaved. The track was always faster than other tracks NASCAR raced at and several cars in a "train" were faster than single cars or smaller trains. This ...
8
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2answers
583 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 ...
14
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2answers
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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 ...
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4answers
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Why is 55-60 MPH optimal for gas mileage of a passenger car?
My driver's education teacher back in high school said 55 MPH is optimal for gas mileage of a passenger car. Just last week, I read an article in a magazine saying 60 MPH is optimal. These numbers are ...
2
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1answer
238 views
Limitations of drag equation
The magnitude of the air resistance for objects with Reynolds numbers greater than 1000 is given by the formula:
Why it does not hold for objects with lower Reynolds numbers? Can I use this ...
2
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0answers
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What kind of shape has the lowest flutter wind speed?
What kind of shape has the lowest flutter wind speed and is the most unstable?
I mean for rigid body.
Thanks
Yes, I know many factors affect the flutter in a MSD system (for rigid body), however ...
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1answer
221 views
Is this simulation following real physics?
I am trying to simulate a game in Box2D(Physics engine). The game that I am trying to simulate is very simple and can be found here: http://www.makaimedia.com/#/speartoss
What I want to know is that, ...
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0answers
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effect of internal force to a glider's descent [closed]
Imagine a glider is airborne in a breezeless sky. The glider is 3 KM high, is traveling at 100 KM / hr, and is descending at a constant rate of 10 m per min. The glider weighs 200 kg. The sole ...
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2answers
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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 ...
