Questions tagged [lift]
Lift is the aerodynamic/hydrodynamic force on a body moving through a fluid that opposes the force of gravity. DO NOT USE THIS TAG for elevators. For aerostatic/hydrostatic lift in fluidstatics use the [buoyancy] tag instead. For EM forces use the [levitation] tag instead.
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Calculating upwards drift velocity of hydrogen in air, where is the error in my calculations?
I have the following problem: I'm charging a lead-acid battery in a
container. The charger could fail, producing too many amperes at too many
volts. Too many amperes I can easily handle in a fuse, so ...
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A rotating cylinder that is free to reorient itself, that is placed within a wind near a surface, will it prefer to orient itself in a certain way?
When there is wind at a surface, and a rotating cylinder is placed there, mounted in a way that it is free to reorient itself, can it be predicted if the cylinder will align itself in a certain way?
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Forces On Toroidal Wind Tunnel wihen Wing is attached inside? [closed]
Consider the attached Toroidal wind Tunnel.
The Wind tunnel is in Vacuum and the moving air and the attached wing are only inside the toroidal tunnel.
Will the mounted wing on the walls of the tunnel ...
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Lift and drag forces in parachuting
EDIT: guys, I am not a physicist and it is not my study field, So even if you see my question is silly to be answered, I hope you can give me a clue.
I hope you are doing well.
I have some questions, ...
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How can you tell that the aerofoil has an asymmetric section only by looking at Lift to drag ratio against AOA?
I am new to aeronautics and I am interested to know how can the section of an aerofoil be determined just by looking at its lift-to-drag ratio against angle of attack ( $C_l/C_d$ as a function of AOA)....
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How does the newton's third law generate enough lift to make the airplanes fly? [closed]
How does the newton's 3rd law generate enough reaction so as to make the airplanes fly to great heights? The airplanes push air downwards but really is that enough to make the airplanes fly to great ...
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Why does blocking a fan speed it up?
Blocking a fan makes the blades speed up. This is easiest to observe with a vacuum cleaner: the motor increases in pitch when the nozzle gets occluded. Why does making it harder to pump the air ...
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Is it possible to statically generate lift with the difference in pressure like wings?
If I understood it correctly, the shape of the wings and/or propellers generates lift/thrust with the difference in pressure in both sides of the wings/propellers; where the lower side has higher ...
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How can an airfoil create more lift than drag?
According to law of conservation of energy, energy can only be converted, not created.
Airfoils convert airspeed to lift, or to put it differently, they create a positive lift force by creating a ...
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Why can't I pump something full of electrons and use it as a hoverboard?
Why can't I pump something full of electrons and use it as a hoverboard? I'm not sure how to calculate how many electrons a material can hold.
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How does torque frequency affect a wing's movement? [closed]
Preface
I'm playing with a python based simulation in which I solve the ODE $I\ddot\phi=\tau_{motor}-\tau_{drag}$. This ODE represents Newton's 2nd law (in terms of torques) of a wing that is attached ...
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What is the main role of the Angle of Attack of an airplane, as in mainstream explanation of lift? [duplicate]
The question is conceptual and simple, it needs no more information to answer it. And I wish not to influence the answerer.
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Where can I find the theory of lift? [closed]
Website, paper, book, anything that contains the whole theory.
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Why a simple theory of lift like the one described below, is not accepted? [closed]
Why a simple theory of lift like the one described below, is not accepted?
If you don’t agree with the following, please just skip this question and do not delete or downvote it, because it is a ...
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What are the methods to measure drag caused by an airfoil in a common high school labatory?
I am currently planning to do an investigation on aircraft flaps. I am trying to find a correlation between the angle of the flaps setting and the lift-drag ratio (coefficient of lift over the ...
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Where is energy for work performed by unpowered objects coming from?
Let's consider two simple effects for which equivalent everyday examples are easy to find:
A helium balloon lifts a piece of rock from the ground into the air.
A permanent magnet lifts a nail off ...
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Can ultrasounds generate lift?
Imagine a plate, the bottom side is flat and the top has dimples (or other structures that increase surface area)
If we vibrate it ultrasonically left and right wouldn’t it experience lift because of ...
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How to calculate the energy and power of the force of lift that acts on a cruising plane?
Say we have a plane flying at constant speed and altitude. Looking at the y axis, the lift cancels out the force of gravity as it maintains constant height. I want to calculate the energy used to ...
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Helicopter hover flight question
I'm an avionics technician and I work on helicopters. This week I was trying to explain where comes the lift force to some friends. I'm a self-learner but I have a poor physics school background.
I ...
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Can a balloon start from Earth and fly to the Moon, using Helium for lift to the top of the atmosphere and then as propellant?
The JP Aerospace's Tandem airship achieved a record-breaking 28,982 meters for the highest airship flight.
After reaching this height, can the helium balloon be used as a propellant, the same way if ...
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Antigravity force in powered precession gyroscope [closed]
I have an idea that a powered for rotation gyroscope with fixed precession can serve as antigravity engine. I also wonder of someone tried an experiment to prove that it does not work.
The following ...
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Convert BLDC motor thrust in grams ($\rm g$) to Newton ($\rm N$)
I am making a quadcopter with takeoff weight equal to 2 Kg. Using thrust to weight ratio of 3:1 the required thrust per motor is 1500g. (No experimental thrust has been obtained for thrust.)
Now I am ...
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Stability of a crate lifted with a lifting beam and two slings when the center of gravity is above the attachment points of the slings
I have a hard time understanding the stability of a crate lift when using a lifting beam. Consider the system in the first figure, where a crate is suspended in two lines using a lifting beam. Presume ...
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What happens to the distribution of the induced angle of attack, if we suppose the circulation distribution is constant?
Assuming the lifting-line theory, we know the circulation must go to zero at the tips of the wing. Therefore, I wonder if we can actually conceive such an idea as a constant circulation across the ...
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What is the weight of an object that accelerates upwards?
I belong to the aerospace community, and a basic concept among the people of this community is that an aircraft is called to be in 'steady flight' when the lift force balances out the weight of the ...
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Can astronauts fly like birds in the space station?
Can astronauts fly like birds in the space station? The space station is microgravity, and astronauts can't walk. Can we design a pair of wings for astronauts to fly in the space station?
What if the ...
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Could super-heated gas allow for Dirigibles/Zeppelins/Balloons to go higher than 60 km of altitude?
Well, I don't know much about physics in general, so I hope I don't make too many misconceptions.
So, from what I could read in this Wikipedia article, the balloon named "BU60-1" achieved ...
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Can the UAV fly in the space station? Can birds also fly in the space station?
Can the UAV fly in the space station? Can birds also fly in the space station?
Birds can bump around the space station.
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Which is correct related to lift: Bernoulli's theory or Newton's theory? [closed]
I was trying to find out how exactly is lift generated. I came across Bernoulli's theory and Newton's theory. But I no where found which one is correct. Can someone help me out with this?
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How do flat insect wings generate lift?
The traditional Bernoulli explanation of lift depends thoroughly upon a wing which, through differing geometry between the upper and lower wing surfaces, causes higher air velocity above and below, ...
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Circulation around airfoil implies infinite kinetic energy, but where from?
The standard model for the circulation around an airfoil is $W(z) = C \log(z)$, which implies that the velocity around an airfoil moving through a 2D fluid at rest goes $\sim 1/r$ with increasing ...
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If Bernoulli's Principle can only be applied to a streamline, how does it justify the pressure difference that causes lift?
According to the Bernoulli's principle, an increase in the speed of a fluid causes a decrease in pressure.
In the case of an aerofoil or aircraft wing, the speed of the fluid (air) above the wing is ...
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Is the downforce of rain on airplanes negligible?
Is the downward pressure exerted by raindrops in even a strong storm on a lightweight aircraft negligible?
Someone better informed may likely improve the following reasoning, cobbled together from ...
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Would a rotating sphere placed within a pipe with air flowing through it experience a lifting force due to the Magnus Effect?
I am wondering if a rotating sphere placed with a pipe/duct with air flowing through the pipe will cause the rotating sphere to experience a lifting force due to the Magnus Effect.
Moreover, if the ...
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The lift of an airplane is similar to that of a balloon. It uses the density difference of air, right?
The lift of an airplane is similar to that of a balloon. It uses the density difference of air, right? The air density on the top surface of the balloon is low and the air pressure is small. The air ...
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Can spinning increase lift of an air balloon?
If we spin an air balloon, the centrifugal force would cause it to expand, since it is directed outwards. Increased volume of the balloon would increase the buoyant force. Can this be used to ...
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What is the difference between buoyancy and buoyant force?
We were solving this question, then the instructor mentioned like Buoyancy force is due to pressure difference, what does pressure difference has to do with upward force?
Upward force should be the ...
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Confused about what makes air follow a wing
I already asked the same question and got great answers but im also confused.
One of the answers said that I can imagine that, because air over the wing has a higher pressure than the air right above ...
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Correctness of a certain physical model for calculating the lift acting on a spinning and stationary frisbee
I just wanted to check if the fundamental physical principles of the following calculation of the aerodynamic lift acting on a rotating frisbee without translational motion, are correct. I assume a &...
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What direction is aerodynamic lift in?
So I was researching about aerodynamic lift, in all the research I read it says lift is perpendicular to the flow direction. But in 3d space there isn't only one perpendicular vector to a given vector....
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Why do curved flows accelerate?
So I’m a bit of a fluid dynamics nerd, but for a while now this has been bothering me. We know that wings produce lift in part because of the flow accelerating over the top of the curved wing, and as ...
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Possible for Magnus effect to overcome rotational phenomena?
I’ve noticed that when a moving, rotating disk is in contact with a surface, it curves the opposite way it is spinning (eg, a puck on a table moving forward and rotating clockwise would curve left). ...
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What is the reason for this lift force?
Refering to this closed question, I made a test using a fan, a styrofoam sheet and a scale as shown in the fig (a) and (b)
Part of the weight of the sheet is supported by a rod close to the wall, and ...
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Magnus effect -Direction of the resultant force experienced by the spinning ball
Consider this picture:
This picture shows the effect of Magnus Effect experienced by a spinning ball in air.
My text says the following:
The figure shows the streamlines of air for a ball which is ...
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Bernoulli and flight
Am not a physicist but Bernoulli's principle states that when fluids flow faster lower pressure is created, thus explaining lower pressure on the top of a plane wing... But in the case where the air ...
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Trains - can aerofoils reduce friction?
Trains need energy to overcome friction at the wheel-rail interface during constant high speed speed running.
Aerofoils on the roof could provide lift, reducing the friction and potentially saving ...
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Are the lift and drag force on a wind turbine blade responsible for torque development?
Is the lift and drag force on a wind turbine blade are responsible for torque development?
I understand that the torque and thrust are the decomposition of the net aerodynamic force on the turbine ...
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Is it possible to lift a bald person with an airstream? (Coanda effect and Bernoulli's principle)
Lately, a high school teacher called Bruce Yeany has been uploading some fluid dynamics demonstrations on his YouTube channel. Here's his first demo video using various objects like vegetables and ...
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How much vacuum is needed to lift?
Just like a balloon of Helium lifts about 1.02g for being less dense than the air. Does the same principle applies to vacuum being less dense than air? And if so, how much can a ballon (1L) of vacuum ...
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What is the bare minimum of air density you need to fly a helicopter?
How high will a helicopter be able to fly before the propellers have not enough air particles to achieve lift?
What is the minimum air density needed to achieve flight with a helicopter?
Could you ...
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