Questions tagged [aircraft]
Aircraft are man-made vehicles intended to operate while flying through Earth's atmosphere.
218
questions
0
votes
2answers
31 views
How does pressure become velocity in a jet engine axial turbine?
All right. Here's what I understand about axial turbines:
It is an axial compressor in reverse.
An axial compressor forces air to flow in an increasingly tight space, where there is not enough ...
0
votes
2answers
35 views
How can a fighter jet pilot pour water from a bottle to a cup without spilling while doing barrel rolls?
I came to watch two videos related to fighter jets, one in which the pilot pours red bull in a glass and another in which pilot pours water from a bottle to cup while doing rolls and while being ...
-2
votes
2answers
59 views
How much at least should the Earth be smaller so that we notice these three phenomenons?
The Earth is moving with a speed of about $1670$ $km/h$ around its axis. This speed is more than the sound speed. So the Earth is always breaking the speed of the sound. How much at least should the ...
0
votes
1answer
104 views
Why can a helicopter fly upside down?
I saw images and video clips of helicopter flying upside down, so it can't be bernoulli principle or angle of attack of the rotary blades. So how can the upside down helicopter provide lift in this ...
2
votes
0answers
46 views
Drag and lift as a function of speed
Assuming turbulent flow, the drag force $F_\mathrm d$ and the lift force $F_\mathrm l$ are usually given in terms of the following equations
$$ F_d\, =\, \tfrac12\, \rho\, u^2\, c_d\, A $$
$$ F_l\, =\...
0
votes
2answers
94 views
Reason for lower air pressure above an airplane wing
I am posing this question from the perspective of a novice. I read an article, from Scientific American, titled "No One Can Explain Why Planes Stay in the Air". The article explains how, while we ...
0
votes
1answer
31 views
Fluid Dynamics (Air) Specifically Aeronautics
An airplane lifts off when the pressure of air pushing down on the wing is reduced due to the speed of the vehicle.
Would it be possible to construct an airplane so heavy that it would be totally ...
1
vote
2answers
71 views
Problem involving the 4 forces that maintain an airplane in level flight
The 4 forces affecting an airplane in level flight are gravity, lift, thrust, and drag. By
altering one, the others are affected. My question is could a wing (retractable) be installed on top of a ...
-2
votes
2answers
158 views
How can Lift = Weight; if airliners fly with Thrust-to-Weight ratios = 0.3? [closed]
Question:
I'd appreciate it a lot if anyone could explain how the wings can generate lift that is 3.3x more than engine thrust? Is there any experimental proof that this? Or is the assumption that ...
-5
votes
1answer
101 views
Lift => Mass, for a helicopter in a hover; not Lift = Weight? [closed]
Background: According to Newtonian mechanics, a helicopter in a stable hover accelerates ('a') a mass of air ('m') downwards to generate a downward force; according to Newtons 2nd law (Force = ma). ...
-2
votes
1answer
64 views
An interesting query about gravitation [duplicate]
If a helicopter flies linearly in the upward direction from a point A on the earth stays in the air at the same position for a long time and then linearly comes down , will it land at the same point A ...
-3
votes
3answers
57 views
If the aircraft has no inertia, how will it move after losing power?
If the aircraft has no inertia, how will it move after losing power? I think because of the aerodynamic force, the aircraft stopped moving immediately. Am I right?
57
votes
7answers
8k views
Is the weight of the aircraft flying in the sky transferred to the ground?
Is the weight of the aircraft flying in the sky transferred to the ground? Is the weight of people swimming in the pool also transferred to the ground? How can we prove it?
0
votes
0answers
10 views
speeding up airflow over wings while keeping the propulsive efficiency?
So, let's say we have an aerofoil and we were to apply thrust at where the air speed was the greatest. See figure:
Since we apply a thrust to the air it will speed up, thus reducing the pressure even ...
1
vote
2answers
135 views
Is a square tube more resistant to bending than a round tube?
In considering tubular forms for aircraft construction, I am reasoning that a square form (or I-beam) would be more resistant to bending (if the load is directly perpendicular and in the plane of the ...
0
votes
1answer
91 views
Conservation of angular momentum on a drone
As I understand, a drone turns horizontally using conservation of angular momentum, accelerating rotors going to one side and deaccelerating the others. All the books I have seen about this say the ...
1
vote
1answer
91 views
What's 'force per second'?
For example, if a force of 10 N per second (10 N/s) is applied to an object, does this have a name or a definition? I'm not referring to impulse - which is Ns.
An airplane's engine thrust is simply ...
0
votes
4answers
141 views
Why donāt people on an airplane experience āweightlessnessā?
People in the ISS feel weightless because they are in perfect orbit around the Earth, and only gravity is pulling on them. By that logic, why arenāt people in airplanes weightless? A plane stays at a ...
0
votes
0answers
51 views
Why can't we fly aeroplane or shuttle directly into the space (beyond 100 km height above Earth's surface)? [duplicate]
Without rockets can we go beyond Karmans line by shuttle or plane?
3
votes
4answers
146 views
Why doesn't my flight aerodynamics maths work? [closed]
Context:
For some context, I'm a game developer and I'm building a flight sim game. My goal is to have realistic flight physics -- not arcade physics.
I'm having issues with the maths -- it is not ...
-1
votes
2answers
60 views
Nuclear-powered Ramjet + criticality
I came across this Wikipedia entry about Project Pluto; a nuclear-powered ramjet that the U.S. was developing back in the day.
https://en.wikipedia.org/wiki/Project_Pluto
This missile would have ...
0
votes
1answer
122 views
How much kinetic energy does a helicopter use in a hover? [duplicate]
A helicopter just circulates air in a hover and maintains a stable altitude. So, how much energy is used to do this? Using the standard equation $KE = \frac12 mv^2$; then the kinetic energy used would ...
0
votes
0answers
20 views
Center of lift in an aircraft
what is center of lift in an aircraft? How is it different from aerodynamic center and center of pressure? Why is COL important?
3
votes
2answers
144 views
Is the physics behind planetary travel simpler than atmospheric travel?
I've been watching a bunch of documentaries lately and had a question that I couldn't really figure out the answer to online. When spacecraft travel through space, are the equations and physics used ...
0
votes
2answers
336 views
Calculate work done by a hovering helicopter over time
This is likely to be very simple, but...
How does one calculate work done by a hovering unmoving aircraft over time?
As in work in Joules.
In this scenario, to remain hovering the aircraft has to ...
20
votes
4answers
4k views
Why do jet engines sound louder on the ground than inside the aircraft?
Everyone is familiar with the whirring sound of jet engines when seeing an aircraft taking off from a nearby airport. It is distinctly very loud on the ground and one can hear it even when the ...
-1
votes
1answer
48 views
Drawbacks of a Tip jet helicopter [closed]
A Tip Jet helicopter offers some advantages, i.e. eliminates transmission, torque is lower, etc.
Engineers experimented with this design in 1950s, but remains marginal at best.
What are the ...
3
votes
1answer
115 views
Why is it a sonic “boom” and not a sonic “boooooooooooooooo…m”?
As I understand it, when an object pushes past the sound barrier, a sonic boom doesn't happen just once, but rather, continually (correct me if I'm wrong). So why is it that there seems to be only a ...
0
votes
4answers
305 views
The physics of airplane flight [closed]
Physics in schools teaches two contradictory and mutually exclusive things: (1) That the upward lift force on an airplane in flight equal its weight (Lift = Weight = mass x gravity). This is based on ...
0
votes
1answer
50 views
Why an aircraft or a ship produce pressure waves both in front and behind them?
I think it is obvious why a pressure wave is produced in front of a moving object but why the rear of it should produce a wave?
1
vote
2answers
41 views
Is plane altitude limited by engine power and if so does air density cause this?
I notice that, for example, human-powered flight operates at low altitudes. This might of course be due to safety but I wonder if in fact the delta in air pressure is greater at lower altitudes and ...
0
votes
1answer
50 views
Why do planes use 1-2 propellers in the front, but drones have 4 on top? [closed]
Planes with propellers normally have one or two propellers in front, facing forward, helicopters have one on top facing up and one facing the side, and drones have four on top facing up.
How do the ...
5
votes
2answers
108 views
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 ...
1
vote
0answers
22 views
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 ...
0
votes
0answers
71 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 ...
2
votes
1answer
51 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 ...
3
votes
0answers
347 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 ...
2
votes
1answer
293 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 ...
1
vote
2answers
270 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 55ā¦ N. Find the angle through which it must tilt its wings to compensate for the horizontal component of the Coriolis ...
0
votes
0answers
27 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 ...
0
votes
2answers
68 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 ...
2
votes
1answer
99 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 ...
0
votes
1answer
100 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 ...
0
votes
1answer
50 views
Motion of a contrail āvortexā
I want to understand what causes this motion on contrails (Cirricular motion) and itās name if possible. What effects it? How and why is it formed?
1
vote
0answers
105 views
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 ...
3
votes
3answers
99 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. ...
2
votes
1answer
306 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, ...
0
votes
1answer
48 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 ...
-2
votes
1answer
33 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 ...
-1
votes
1answer
73 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, ...
