Questions tagged [lift]

The force acting on an aircraft in opposition to gravity which keeps the aircraft in the air.

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96 views

At which angle tiltrotor's rotors generates more lift?

[Tiltrotor 1] [Tiltrotor 2] I can't name these tiltrotors. I just want to know which of the tiltrotors generate more lift considering aerodynamics and based upon the rotors ...
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1answer
426 views

What effect does the angle of attack have on lift and drag?

In general, what effect does the angle of attack have on lift and drag? I understand the the B-25 take-off run was normally in excess of 1500 ft, the exact value dependent upon load, density altitude,...
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4answers
825 views

What would be a simple aerodynamics simulation software for a student? [closed]

I have a project due 2 weeks from now that demands we make a glider using Styrofoam. I'd like to simulate the results as I plan my glider before I build it. Which simple software, which allows ...
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2answers
274 views

When rearranging the lift force equation to solve for lift coefficient instead of lift force, why is the numerator often given as F not 2F?

the standard description of the Lift force affecting the lift surface is: $$ F={\dfrac{1}{2}}\rho v^{2} SC_{L} $$ the basic rearrangement gives the following definition of the lift coefficient: $$ C_{...
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1answer
45 views

What are the best methods for calculating lift during different stages of flight?

Supposing I have the all dimensions of an RC airplane: wingspan, NACA airfoil, aspect ratio, fuselage length, etc., what would be the best methods of calculating the expected lift the aircraft should ...
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1answer
60 views

Why generation of lift is more at mid span of the wing?

For the same condition like same density, wing area, free-stream velocity, From the above figure one can see more pressure differential and hence more lift at mid span of the wing? What causes this ...
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1answer
101 views

What was the lift-to-drag ratio for WWI biplanes?

I will be interested to know what was the lift-to-drag ration for a few more known WWI biplanes at take-off, cruise and landing speed; with the propeller running, stopped or non existent (tests in ...
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1answer
142 views

How does vorticity change the lift coefficient of an airfoil?

For airfoils in unsteady motion, the lift coefficient oscillates and the wake is characterized by vortex shedding. How does vortex shedding affect the lift coefficient for an airfoil?
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1answer
159 views

Tapered Wing Providing low Coefficient of Lift

Hi I am currently analyzing different wing designs using ANSYS Fluent. One of my designs has a straight leading edge but a swept trailing edge thus it is tapered with wing root chord at 50mm and wing ...
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1answer
184 views

Was the Coanda effect known in 1868 to Matthew Piers Watt Boulton (the one who described the first ailerons)?

Matthew Piers Watt Boulton is known as the inventor whose 1868 British patent No. 392 nullified any claim of the Wright brothers that they discovered the ailerons (see FIG. 5-7). It seems now that ...
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2answers
85 views

How do rotorcraft achieve lift?

How do rotorcraft (helicopters, and other rotary aircraft etc.) achieve lift? I mean, obviously the rotor. But who knows the specifics? What are the physical, mechanical requirements of a rotary ...
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2answers
581 views

Is it possible to obtain the lift and drag coefficients of a 3D body in ANSYS Fluent?

Is it possible to obtain the lift and drag coefficients of a three dimensional body in ANSYS Fluent? Or, would it be acceptable to take the coefficients of several cross-sections along the wings and ...
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0answers
66 views

Is there any bibliography for triplane aircraft design?

I've been tasked with designing an RC aircraft that has the greatest lift force for a specified wingspan, total length and takeoff velocity, and thus have been studying the different wing ...
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39 views

What is the effect of wing flex on wing's airfoil shape and its performance effect on wing?

There are good amount of discussion on wing flex in this forum. I am more interested in understanding the effect of flex on aerofoil shape of the wing and its impact on flight performance. Do ...
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1answer
59 views

How could I find the air velocity and lift force?

As shown below I have this information as shown below in the picture. I got the density according to the ISA standard 𝜌 = 1.225[kg/m^3] and 𝐢𝐿 = 𝐢𝐿𝛼 (π›Όβˆ’π›Ό0) is calculated as below : Ξ±=βˆ’4: CL=...
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2answers
3k views

How could I find 𝐶𝐿𝛼 lift coefficient slope?

I'm trying to find 𝐢𝐿𝛼 lift coefficient slope through the below diagram, could anyone explain for me please, how could I find it? by the way, I depend on this equation 𝐢𝐿 = 𝐢𝐿𝛼 (π›Όβˆ’π›Ό0)
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What is the relation between solidity and lift coefficients?

I've seen this graph in a couple of places. I'm not sure what it's supposed to mean, as the formulae I've seen in the papers cannot be found in any standard book or reference. Please let me know if ...
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111 views

How much lift can be generated by the intake lip of a duct?

How to calculate the extra lift gained by the intake lip of a duct? Aside from improving efficiency by preventing tip vortices, if a duct has a bell-shaped intake, this lip around the edge creates ...
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0answers
393 views

How do you determine the lift coefficient of a finite wing using the coefficient of an infinite one? [duplicate]

How assuming I know the lift coefficient of an airfoil/infinite wing, how do I then use this value to calculate the lift coefficient of a finite wing? Please quote your sources. Many thanks,
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0answers
408 views

Where does the lift act on a B747-400 wing when the aircraft flies straight and level?

I'm doing a math exercise and I'd like to understand: Where does lift act overall on the wing of a B747-400 when the aircraft flies straight and level at its cruise speed. Which parameters, if any, ...
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1answer
87 views

How can the lift induced drag for a wing be calculated?

I have found a lot of information to calculate drag coefficients and I know that total drag can be calculated by $$ D = \frac{1}{2} \rho u^2 S C_d $$ However I was wondering, if I substitute the zero ...
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1answer
83 views

Calculate g's per radian

I'm currently attempting to assign handling qualities to the A-4D, and I would like to know how to find the term: $ n / \alpha = \overline{q} \times C_{L\alpha} / (W / S) $ where $C_{L\alpha}$ is ...
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2answers
663 views

When the angle of attack is increased does the air flowing below it slow down [duplicate]

So the air above the wing flows faster. So it creates low pressure above the wing. The air flow below the wing, is it slowed down by the increased angle of attack or does it stay the same? So is the ...
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104 views

Lift Pressure Distribution [closed]

If the pressure goes always from high to low, we should have a compression, due the lower pressure of the air stream over the upper surface, and an expansion in the airstream in the lower surface. So ...
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3answers
672 views

How much lift is created by a half-sized rotor?

I wonder if lift is directly proportional to the diameter of the rotor disc. For example, if an engine spinning a 26 ft diameter rotor can lift 635 kg, will a 13 ft diameter rotor using the same ...
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4answers
436 views

How fuselage creates lifting force when plane flying on a side?

On a question "How plane able to fly on a side" people answer that it's because fuselage shape crate lifting force and plane should have enough thrust. But that seems vague to me. How fuselage creates ...
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2answers
499 views

How to adjoin wing skin to wing ribs?

I saw a youtube video (from a channel called Real life guys) where gum was used to join the ribs of their homemade plane to the skin and I saw another video where the wing skin(tedlar) was literally ...
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3answers
244 views

Would a flying-wing drone fly farther if filled with helium?

I'm wanting to build a flying wing designed drone and I'm wondering if I were to fill the fuselage with helium if it would improve it's range.
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53 views

Is lift/drag the same as coefficient of lift/coefficient of drag?

I see it being used interchangeably (for example by Airfoil Tools Fusion360 AddIn), so can I just pick an airfoil from the airfoiltools database with a certain CL/CD for my aircraft and assume L/D is ...
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2answers
131 views

Does bi-wings create essentially double the uplift as single wings?

This puzzles me a bit, and I cannot find the answer anywhere. Does bi-wings create essentially double the uplift as single wings?
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159 views

How much can 3 fans 7 inches in diameter and each a generating 160 cubic feet per minute airflow rate lift? [duplicate]

I'm working on a hoverboard project and am having trouble finding out the maximum weight these fans could lift.
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275 views

Why hasn't anyone tried making two propellers facing upwards and the other two facing downwards? [closed]

Within a quadcopter, I know usually it's all the propellers facing upwards or all of them facing downwards. Why hasn't anyone tried making two propellers facing upwards and the other two facing ...
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2answers
318 views

Are high-frequency flapping wings efficient and scalable at high Reynolds numbers?

Is high-frequency flapping (similar to how dragonflies fly) an efficient lift production method at high Reynolds numbers? I have not seen anyone develop wing suits with high frequency flapping, is ...
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1answer
1k views

Is pressure lower than ambient on the pressure (bottom) side of an airfoil? [duplicate]

I've been reading about this for quite some time and thought I understood it. Then somewhere someone mentions that air under the wing has higher velocity than ambient thus a lower pressure than ...
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122 views

Is it better to reduce drag or increase lift?

Essentially my question is, in general is it better to have a lower drag or a larger lift. I know lift to drag ratios are used as an indicator but I think these don't give the best picture. For ...
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1answer
241 views

Does thin airfoil theory work at very high angles of attack?

Thin airfoil theory says that lift coefficient is directly proportional to the angle of attack in radians. I haven't been able to find any limit, short of stall, for applying this theory. It would ...
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1answer
282 views

What is area in equation of lift?Does it remain constant during flight? [duplicate]

I am beginner & learning aerodynamics concept. What is area in equation of lift(L) =Coffecient of lift x area x density x square of velocity/2. Does increase in angle of attack increases the area &...
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5answers
232 views

Can lift be increased by increasing the angle of incidence of the wing? [closed]

Can the lift of a plane be increased by increasing the Angle of Incidence (angle between the chord line of the main wing and the axis of the fuselage)? Meaning, can more lift be generated while the ...
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1answer
606 views

How do we derive Lift Coefficient of an airplane's wing?

In many references I read that lift coefficient ($C_l$) is a product of wind tunnel test. But many times I read the formula to calculate the coefficient of lift. From the lift equation, $$L=\frac{1}{2}...
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1answer
283 views

Why do I see moisture coming from the middle of the wing as well as wingtip vortices? [duplicate]

A lot of times I see small tube like streams of visible moisture training from the middle of an airliners wing. I assume this is induced drag created by wingtip vortices, when the aircraft is heavy, ...
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632 views

Do wingtip vortices cause a decrease in the lift component of aerodynamic force, and do planes need to pull more AoA to compensate?

So, from what I know about wingtip vortices, they shift the angle of the relative airflow to where the effective angle of attack of the airfoil is lowered. Since the aerodynamic force is always ...
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2answers
63 views

How to calculate CL with the use of MTOW?

I have a problem that it gives us the MTOW of a UAV (200 kg), the speed and the reference area. So its probably easy to find the CL knowing that it flights at steady level flight (L = W). I'm confused ...
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1answer
135 views

Is lift generated only by wings? [duplicate]

In modern aircraft is lift only generated by wings or can other parts of fuselage generate a significant amount as well, to the point it needs to be accounted for when designing a plane?
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3answers
445 views

If we use upper surface blowing and externally blown flap on the same wing will lift correspondingly be very high?

With two engines, one above and one below the wing, will the lift be the sum of two lift increments (produced by upper surface blowing and external blowing)? I am trying to make a jet suit and I am ...
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311 views

Drag coefficient and lift coefficient [closed]

What happens if drag coefficient increases but the lift coefficient remain the same?
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74 views

Center of Pressure(CP) [duplicate]

The center of pressure is: A)The point at which the Total Aerodynamic Force acts B)The point where the lift force acts C)The point where the resistance force acts Only one answer is correct,i think ...
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26 views

Why does the tapered part of the wing has high coefficient of lift? Like a Delta wing design

If we take a Trapezoid wing shape as an example and see that it has low π‘π‘Ž near the root of the wing and very high π‘π‘Ž at the tip. The Lift generated, however, is reversed to the that of the π‘π‘Ž. ...
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43 views

increasing lift in a plane by placing engine in such a way that the air coming out of it washes over the wings to create more lift [duplicate]

I was wondering if the engines of a plane can be placed in such a way so that the air coming out of the engines goes from over the wings so that the velocity of air over the wing is higher and more ...
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0answers
23 views

Computing Cl using Cp values? [duplicate]

So, from a Lab, I have Cp values for an incidence corresponding x/c on the upper and lower surfaces and I would like to calculate the Cl value at this incidence. I'd like to do this through python, so ...
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22 views

Whats the effect of aerofoil camber and thickness on Clmax and Cdmin?

Does anyone have any experimental references/wind tunnel testing testing data for various thickness and/or camber?