Questions tagged [lift]
The force acting on an aircraft in opposition to gravity which keeps the aircraft in the air.
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Why does this site allow misleading answers to remain, and stay at the top of the stack? [migrated]
In searching for some relevant photos for a lecture I am writing, I came across a question "Does lift equal weight in a climb?". The first answer, with most upvotes, is not only very ...
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Why does pressure difference between top and bottom surface of wings increase as speed increases?
We observe that lift force increases as speed increases on aircraft wings. Theoretically, there must be increase in pressure difference between top and bottom surface of wings.
What I don't understand ...
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Need help relating calculating Helicopter Lift [closed]
I’m a student doing a project on the relation between angle of attack and lift generated by helicopter blades and I'm having a little trouble. I need a method to calculate lift for a set of blades ...
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How do you calculate gripping force of a collet? [closed]
Okay so just to explain my problem. I have a central shaft that has two belt drives connected to it. Each belt goes to a propeller on either side of the drone. I need to connect the shaft that is ...
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Can I identify wingtip stall by looking at the lift distribution?
I'm projecting a wing in XFLR5. The lift at the tip of the wing looks like it's dropping very quickly close to the stall angle, so I think there may be wingtip stall, however, is there any way I can ...
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How to compute the direction of the vector perpendicular to the wing?
I'm trying to compute the direction of the vector that extends perpendicularly up from the top of the aircraft's surface.
Is there a way to compute the vector's 3-dimensional parameters in Cartesian ...
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What flaps are used for, if the aircraft has already landed? [duplicate]
When watching the below clip in the final approach sequence we can clearly hear setting flabs to 1, 2 and then to maximum.
At 12:05 into the clip, when fully landed ...
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Impact to lift curve slope for a tapered wing with only trailing edge sweep?
I'd like to use a tapered wing with 0 deg leading edge sweep and 12 deg trailing edge sweep as shown below for my RC model. I understand that lift curve slope, a, is reduced for wings with leading-...
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How to determine the required twist in the Bell Shaped Lift Distribution (BSLD)
I'm doing a research about flying wings and BSLD and I'm having trouble to find the required twist. I'm using the equation L = ( 1 – x^2 )^3/2 to find the local load (Bowers, 2016). But how can I ...
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Why should the leading edge of the horizontal tail be lower than the trailing edge? [duplicate]
As mentioned in this answer: https://drones.stackexchange.com/a/2564/5088
The leading edge of the tail should be lower than its trailing edge, providing some "down force" in flight.
I am ...
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What makes the MV-22 has lift thrust and its disk loading is so high?
Image source:
The above is comparison table of several rotating wing aircraft's disk loading, especially I highlighted the disk loading of MV-22 Osprey tiltrotor versus CH-47 Chinook helicopter. As in ...
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Can wingtip vortices formed around an unswept wing produce vortex lift?
Vortex lift is a kind of aerodynamic lift force due to vortices formed along the leading edge of highly-swept (usually 60 degrees of swept angle or higher) wings at high angles of attack. The "...
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Is there a formula for calculating lift coefficient based on the NACA airfoil?
Are there any formulas that can be used to calculate this?
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Is increase in lift allways follwed by increase in drag and vice versa?
We look at lift,drag and L/D at multi element wing with slots and same wing shape just without slots.
wing without slots:
Completly top side is stalled, so here is all low pressure(blue at picture),...
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What should be the size of a lifting body aircraft that can carry 5 passengers (385kg/850lbs)?
So I just want to know the size of an aircraft with a lifting body that would fly at low altitudes (around 40 meters/100 feet), and at low speeds (maximum 200 km/h 124 mph). But I don't know if these ...
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How is lift produced when the aircraft is going down steeply?
If a positive angle of attack (AoA) is needed to produce lift, then how is it created when a plane is in a 30 degree nose low dive?
How does it not stall? At this attitude the AoA has to be negative, ...
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Does Cd number change at different speeds during wind tunnel testing?
When meassure Cd or Cl of airplane/car in wind tunnel, does number change at different speeds, for example at 100km/h compare to 250km/h?
If yes,how much?
I know from theory that coefficents change ...
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Where can I find a list of higher lift laminar airfoils?
Does anyone have a list of laminar-flow airfoils (so I can compare them) with a Cl at 0°AoA of preferably at least 0.4 ?
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How pitch is changed in harrier jet(vertical landing and take off aircraft)
How pitch is changed in harrier jet and lift is achieved?Is it same principle like conventional fighter jets like f16 etc? What about drones quadcopter etc do they also follow same principle?
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Evaluating maximum TAS for a given available power
This is the original problem:
A turboprop aircraft with a weight of 162 kN is equipped with a power plant with a power derating model described by $\frac{P_A}{P_{A,0}} = 0.9\sigma^{0.75}$, where $P_{...
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Will ice on an airfoil work as a vortex generator?
Vortex generators are little fans that generate vortex to attach flow to an airfoil and delay stall. If frost or ice are formed on an airfoil, technically they also generate turbulence and vortex,I am ...
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What are some features of a wing, which effects its lift coefficient other than its sectional view? [duplicate]
What geometrical features of a lifting surface apart from which airfoil it has, I mean the ones visible from the top and front view of a wing (for ex: its span, AR, sweep, dihedral etc.) effects its ...
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What causes lift?
Now this seems to be the question of the ages, and various questions on this site regards it.
The often told description of lift is that it is due to air traveling faster over the wing than under it, ...
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How to choose an attack angle?
I'm writing a little piece of code for preliminary design that can calculate the ideal wing area for a given load, cruise speed and aspect ratio or span. It seemingly works well on the A380 data:
<...
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2D to 3D Non-Elliptical Lift Curve Slope Correction Factor Reference
I'm working on automating some aerodynamic calculations for a particular multidisciplinary design tool and in the course of setting it up I ran across this formula from the input theory manual
$$
{CL_\...
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How does Condensation Affect Lift?
Here are two pictures of condensation happening above the wing:
The condensation happens because the pressure drops above the wing which in turn causes the temperature to drop. When the temperature ...
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What methods are used to calculate the geometry needed to obtain a bell-shaped lift distribution?
In aerodynamics, what methods do people use to calculate the geometry of a wing (and body) needed to obtain a bell shaped lift distribution? Please go into as much detail as possible for a stack ...
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How to calculate lift and drag of commerical aircraft in different phases of flight?
What is the best way to mathematically calculate values of lift and drag forces, in different phases of flight: takeoff, climb, cruise, descent, and approach?
Edit: I have the idea of calculating the ...
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Why does the leading edge vortex accelerate the flow downward?
I know leading edge vortices over delta wings make more lift. I understood that the core of the vortex sheet is low, so there is suction flow that makes lift. But, I can't understand how a leading ...
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Why does lift coefficient not change with velocity in inviscid flow?
Why exactly is lift coefficient constant with velocity in inviscid flow?
(For a given angle of attack, 2D section and fluid, pre-stall etc)
Does it come out in the derivation of lift coefficient or ...
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What does deploying landing flaps do to the (L/D)max and minimum drag speed of an airplane?
I thought that deploying flaps will increase both the drag and lift, thus increasing L/D ratio? But do they increase proportionately? And how exactly does that correlate with the increase/decrease of ...
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Converting 2d Cl to 3d [closed]
I am trying to convert 2d Cl data obtained from javafoil for a NACA 4412 into 3d data to be used for analysis of the airfoil, but cant find any equations online
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Which one produces more lift?
I have come across this question on Twitter. I have found a similar question here. The aircraft isn't flying but just doing Cobra Maneuver. Since the direction of the lift is in the same direction and ...
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Never heard of this Aerofoil?
I just came across this aerofoil, 65-2xx?
I searched this but it doesn’t come up with anything like 65-200 for example but instead SG6051 which is the closest I could find to this?
Am I missing ...
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How can I estimate the coefficient of lift for take off?
For the CLto (take off lift coefficient), is there some way to estimate this?
I was thinking of using CLmax but wouldn’t this be too big? I was thinking maybe CL cruise?
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How do I calculate where a wing is most likely to break?
I want to make a delta wing out of carbon fiber, but I do not know how many carbon fiber layers would be needed to prevent the wing from breaking due to shear stress. What would be the calculations ...
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Why airflow travels faster on upper wings?
I have been looking for solutions and come up with two popular explanations:
Conservation of mass / Continuity
For a positive-cambered wing, the streamlines would be compressed/converged at the ...
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The stall velocity condition: Exactly what is stall velocity? [closed]
Question: if my stall velocity is 20m/s, then...
If the airplane is travelling at a velocity greater than or equal to the stall velocity, can one assume the plane will not stall?
Can one assume that ...
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Can induced drag be negative?
For an aircraft in straight and level flight, lift-induced drag is the horizontal component of the force perpendicular to the wing chord. Positively cambered aerofoils generate lift starting at small ...
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Why does lift decrease and drag increase when approaching the stall condition?
This is an ECQB-PPL question specifically asking what happens before the stall. I do understand that after the critical angle has been reached, the airfoil is no longer generating lift (so obviously ...
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Are horizontal engine pylons generally shaped to provide lift (in either direction)?
Most civil multiengine jets and some civil multiengine propeller aircraft have engines mounted in nacelles on the ends of pylons extending some distance away from the wing or fuselage. Wing-mounted ...
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Is it possible for the lift force unit vector to be equal to the weight force unit vector?
I know that the drag force is parallel to the direction of flow, thus equal to the unit vector of velocity. But if you consider a vehicle, when its angle of attack is below the velocity vector from a ...
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Help with calculate forces from pressure distribution
V=50m/s
deltaPg= -981 Pa
deltaPd=490,5 Pa
c=1m
r.com/PCshZ.png
Above is calculate Fz with integrals and with average pressure.
Why F3 is calculate from 0 to C/2 if pressure distribution is drawn at ...
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How to solve normal and axial aerodynamic force coefficients integral equation to calculate lift coefficient for an airfoil?
$$ c_n = \frac{1}{c} \left[ \int_0^c (C_{p,l} - C_{p,u}) \, dx + \int_0^c \left(c_{f, u} \frac{dy_u}{dx} + c_{f,l} \frac{dy_l}{dx} \right) dx \right] $$
$$ c_a = \frac{1}{c} \left[ \int_0^c \left(C_{p,...
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How to calculate the takeoff speed for a hypothetical aircraft?
Given some basic information such as:
aircraft weight
wing load (including wingspan, and basically the whole wing configuration)
airfoil profile
coefficient of lift
angle of attack
Is it possible to ...
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How to turn inviscid data to viscous?
I have used Panel method to calculate Cp vs x/c graph and CL. But as panel method assumes attached flow it does not give an flow separation and thus in CL vs alpha graph I could not find any stall. My ...
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Why is the CG assumed to be between the CP and the tail?
While discussing stability (Longitudinal, Lateral, Directional), invariably, all texts assume CG to be between CP and tail.
Ex: Look at the specific image in wikipedia https://en.wikipedia.org/wiki/...
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Will air accelerate over a wing and generate lift, if the air has zero viscosity? [duplicate]
Will air accelerate over a wing, if the air has zero viscosity?
Will the wing produce any lift under these conditions?
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Streamline Curvature Theorem applied to Airfoils?
I am new to studying aerodynamics and taking up aeromodelling and am currently learning how lift is obtained in-depth. When studying the two common explanations as to how lift is generated by an ...
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How does a forward lifting surface affect ideal lift distribution of a main wing?
In Peter K's answer to this elliptical wing with lowest drag question the minimum induced drag lift distribution for a wing is described as one with a constant downwash angle across its span. When a ...
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