Questions tagged [aircraft]
Aircraft are man-made vehicles intended to operate while flying through Earth's atmosphere.
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Do planes have to be noisy?
I tend to think of noise as an undesirable waste of energy because the generator was not designed for that purpose. But that doesnt mean this waste can be avoided.
So I wonder how much of this noise ...
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0answers
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Is there a physical limit to silent quadcopters, and what are the parameters?
Quadcopters can now navigate fairly well indoors. One could imagine many possible uses, including telepresence and security, but which are limited because of the loud noise.
Assuming zero 'motor ...
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62 views
Thrust needed from an engine to reach orbit
Assume you had an airplane with magical engines that didn't need fuel, air or power, to operate. What thrust to ground weight ratio would the airplane need to reach orbit? By ground weight I mean mass ...
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1answer
34 views
Derivation of the expression of a propeller pitch distance
The pitch distance of a propeller is given by:
$$p = 2\pi r \tan{\beta}$$
where $\beta$ is the pitch angle and $r$ is the radius.
I cannot find how this expression was derived.
Could you please ...
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0answers
77 views
Lighting an Electric Bulb with Earth's Magnetic Field
Yesterday, I was solving some problems of Electromagnetic Induction. Suddenly a thought struck my mind.
Earth has its own magnetic Field.If an aircraft of metallic body is flying in the air then ...
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1answer
89 views
Why wasn't the Stipa-Caproni plane efficient in its flight?
The Stipa-Caproni was an experimental italian plane design. Though it has a very peculiar shape, it seems at first glance like it would have pretty good aerodynamic profile since its reference area ...
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2answers
89 views
Horizontal component of Coriolis force in an aircraft: compensating force with its wings angle
I have the following problem:
"An aircraft is flying at 800 km/h in latitude 55◦ N. Find the angle through which it must tilt its wings to compensate for the horizontal component of the Coriolis ...
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0answers
24 views
Inverted flight [duplicate]
I've read the answers provided but I'm still confused that if an aerofoil is designed so that air flows faster over the upper surface for the purpose of providing lower pressure and hence lift why in ...
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2answers
55 views
Is lift force proportional to size?
I'm trying to calculate lift force of a particular object I'm working with. However, I can't find much information on how much force is required for an object to stay in flight though.
My questions ...
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1answer
80 views
Principle of Lifting of an Aircraft [duplicate]
While using the Bernoulli's equation to deduce the upthrust on an aircraft , a statement is always made that
The air particles going above th wing have to cover a greater distance in same time than ...
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1answer
87 views
Why dont we account the rotation of the earth in aircrafts? Is it just because of the air or is there more to it? [duplicate]
Today there was a seminar regarding modern air crafts held in my school. At the starting of the lecture, we were asked a question which I found quite intriguing.
"Why does a helicopter or a fixed ...
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1answer
39 views
Motion of a contrail “vortex”
I want to understand what causes this motion on contrails (Cirricular motion) and it’s name if possible. What effects it? How and why is it formed?
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0answers
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Rate of change of heading in terms of normal acceleration and air speed
Let's say an aircraft is traveling with speed $|\mathbf v|$ with respect to an inertial frame. The aircraft is able to execute turns by producing an acceleration $\mathbf a$ that is normal to $\mathbf ...
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3answers
90 views
Strange optical distortion in a video recorded from an airplane window
I recorded this video from an airplane window while it was decreasing its elevation. What is the explanation for this optical distortion? This distortion appeared only in a certain range of elevation. ...
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1answer
113 views
How do you explain the formation of shockwave on the wing surface during near sonic flight?
Explanations of shockwave for the common folks (youtube videos, googling) all tend to focus on successive sound waves generated by the air craft traveling outward in circles (sphere).
That to me, ...
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1answer
37 views
Defining the change in direction due to wind
My question: Which force vector (A, B, C, or D) represents the APPROXIMATE direction in which the boat is travelling as a consequence of the wind?
My approach: I looked for which vector combination ...
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1answer
27 views
Effect of Bodyform on Air Resistance [duplicate]
Visualize those little pictures as the front of vehicles like airplanes and trains. I wonder if I am right about my speculation below, and if so, if somebody could explain the exact reason. Sources ...
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1answer
71 views
How does gravity effect to aircraft in sky?
Aside aerodynamics and buoyancy, Is there a simple way to explain how gravity is negligible in flight paths using free falling body diagram? In a parabolic trajectory,we know that at max height, ...
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1answer
70 views
Why is the polar diagram of an airplane depended on weight?
Can anybody answer this question? Although aviation-related, it is in fact a fluid mechanics problem:
https://aviation.stackexchange.com/questions/54192/why-is-polar-curve-of-a-glider-dependent-on-...
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2answers
137 views
Sonic Boom in Aircraft and Spacecraft
I would like to know why aircraft, and spacecraft produce a double sonic boom on breaking the sound barrier.
A while ago, I thought I got it, as there’s a start and finish point to every vehicle.
...
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1answer
53 views
what would a “ceiling effect” (the converse of ground effect planes experience) entail?
Wikipedia describes ground effect as "the increased lift (force) and decreased aerodynamic drag that an aircraft's wings generate when they are close to a fixed surface."
That's all fair and good, ...
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4answers
135 views
Effect of tailwind on aircraft speed
I have been spending some time in analyzing the impact of tailwind on the ground speed of the aircraft. My analysis is based around the following equation : VAW = VAG - VWG ; where VAW is the velocity ...
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4answers
542 views
What causes the air speed difference above and below the wing of a plane?
I am studying about the lift generated by a fluid flowing on a surface. In the case of an airfoil I have seen that there are various ways to explain it, you can use for example:
the third law of ...
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2answers
80 views
When plane crashes
Could it be true that when the plane is falling to crash, one should start to jump. If the moment the plane crashes, you are in the air then, you are not affected by the momentum. That is very ...
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2answers
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How powerful can the vacuum from an open aircraft window be?
It has been an item of folklore that a "pressurized" aircraft cabin, if punctured will force people through the aperture, a la Goldfinger. However, obviously the pressures inside the cabin (12 PSI) ...
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1answer
70 views
Lightning strike on aircraft
Is an electromagnetic pulse sufficient to account for the complete dscharge of an aircraft struck by lightning?
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1answer
34 views
How would I calculate the speed passengers 'jump' based on the speed and displacement of a plane during turbulence?
I read recently that if I'm in a plane that hits turbulence, the plane might only move 1 to 20ft. However, due to the speed that plane is travelling at (say cruising at 550mph). The passengers in the ...
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1answer
140 views
What does it mean that the weight is negative?
In a recent question on the Aviation Stack Exchange, one explained that would cause an autogyro's crash. Basically, it says that the one thing that would make the gyro crash is to unload the motor too ...
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1answer
91 views
Airplane trails
Some airplanes leave a trail through some regions of sky. This post explains why it is so, but it seems not enough.
The trail is said to be made mostly of water which, on a specific altitude, ...
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2answers
1k views
Flying with or against rotation of a planet
So, I've read a bunch of articles about how, somewhat contrary to intuition, it's usually faster to fly with the rotation of the earth versus against it. All the answers have to do with wind and ...
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1answer
69 views
Would a plane get lighter if dry ice is inside and it sublimes during the flight?
During a series of comments here,
it was suggested that taking dry ice into an airplane, the airplane gets lighter as the ice sublimes.
This was supported by the idea that when the dry-ice sublimes ...
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2answers
85 views
Flow over Airplane Wings
I recently read this from Wikipedia in an article discussing lift.
A fluid flowing over the surface of a body exerts a force on it. It makes no difference whether the fluid is flowing past a ...
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4answers
759 views
Can you “rewind” sound messages by going supersonic? [duplicate]
I was having a discussion with a friend about supersonic flights.
It was then when he proposed an idea on an interesting experiment that can be done during a supersonic flight.
The experiment goes ...
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1answer
176 views
I'm confused about the aerodynamics of a gas turbine compressor blade of a jet engine?
I have a few questions here-
Why do you need an increase in static pressure, why not total pressure?
The rotor vane increase total energy, is this energy converted into kinetic energy or total ...
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1answer
49 views
Could you build a “space tunnel system”? [closed]
With the limitation of fuel that can be taken on a space craft, would it make sense to build a propulsion system in space instead?
For example via rings that are aligned very well and are positioned ...
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0answers
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Cold airplane window frame
I was flying from Asia to Europe and noticed that the bottom of the window frame was ice cold while the top was warm. Why?
My theory: The sunlight warming the air between the "inner window" and the "...
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1answer
22 views
Is Gyroscopic precession relative to the object in precessions axis of movement when there is drag imposed on the disc?
Does my question make sense? I am referring to the disc of an AutoGyro aircraft. Though the fuselage of a modern pusher AutoGyro will weather vane into the wind, the disc that provides lift does not. ...
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0answers
71 views
Why does a car need so much power to get to a given speed compared to an aircraft?
This question has been bothering me for a long time because it seems like it should be obvious, but I can't figure it out. Excuse me if I'm being dumb.
Why does a car require so much more power then ...
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1answer
148 views
If Earth is curve and spinning, why plane flying in high altitude does not delayed?
If earth is spinning globe then the layer of athmosphere have a different tangential velocity for different altitude. For near the ground (solid surface of the earth) then the velocity of the air just ...
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0answers
240 views
What are the 3 Euler angles?
I am currently reading up on inertial measurement in aircraft systems. Euler angles are one of the concepts I am a bit confused with. In an Euler angle-rate matrix there seem to be 3 parameters: p, q, ...
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0answers
72 views
Why don't aircrafts spin their wheels before landing? [closed]
I had this thought when I was on the aircraft when it landed in the runway. It made lots of smoke and all sorts of vibrations, you know.
When I enquired about it, I came to know that the landing part ...
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4answers
943 views
Does a pilot have to take into consideration the angular spin velocity of the earth?
First imagine a pilot takes off from a North South runway situated on a specific northern latitude, the circumference of which is 888 miles, where the angular spin velocity of the earth (and the plane)...
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1answer
317 views
Reynolds number and shapes of airfoils
$$\mathrm{Re} = \frac{\rho \cdot v \cdot c}{\mu}$$
Where $\rho$ is the pressure, $v$ the velocity relative to the airflow, $c$ the chord of the airfoil and $\mu$ the air density.
Does that mean that ...
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1answer
301 views
Why biplanes are not used in modern high speed aircrafts? [closed]
Explain why the high speed and commercial air crafts are monoplanes why not biplanes?
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1answer
178 views
Why does a tail make a kite more stable?
I have looking online to find answer to this question and one answer said that the tail increases drag and weight but, it did not say why the Increase in drag makes the kite stable. One theory I have ...
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3answers
334 views
Why Jet fighters don't heat up like spacecrafts?
After reading the answers to this question: After what speed air friction starts to heat up an object?
I understood that the compression of gas is what generates heat that we see when a spacecraft or ...
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1answer
1k views
Why does an increase in angle of attack cause the boundary layer to slow down?
From what I understand when the angle of attack of a wing is increased enough the boundary layer air slows down. Eventually the air starts moving backwards and a separation bubble occurs. Why does the ...
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1answer
597 views
Ion Wind Thruster? What is the theory behind it?
I am 18 and I am a university student studying aerospace engineering. While I am looking up Elon Musk's Electric jet plane I found this http://inhabitat.com/mit-developing-ionic-wind-thrusters-as-...
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2answers
87 views
Wouldn't the air accelerating over the top of the wing push the wing forward (thrust)
A wing accelerates air on top of itself. Does this cause any forward thrust? I would think so because the air is accelerating backwards which should create an equal and opposite reaction forward.
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3answers
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Why does NASA need an aircraft model flying over a flat and nonrotating earth?
On the NASA Technical Reports Server (NTRS) there's an article titled Derivation and definition of a linear aircraft model:
Abstract
A linear aircraft model for a rigid aircraft of constant ...
