# Questions tagged [lift]

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

16 questions with no upvoted or accepted answers
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### What is the total lift equation of a helicopter with 3 Flettner rotors?

I'm doing research regarding the possiblity of using Flettner rotors on helicopters. I would like to derive the total lift equation for a helicopter that consist of 3 Flettner rotors. Given that: ...
167 views

### How to find the static stall angle of attack for a given airfoil at given Re?

For vertical axis wind turbines applications I'm wondering how one would find the static stall angle of an airfoil at a given Reynold number? Is it just the critical angle of attach (AoA) where ...
61 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 ...
38 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 ...
60 views

### 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 ...
100 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 ...
401 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, ...
82 views

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 ...
52 views

### Why does the Center of Pressure move forward on high-wing airplanes and aft on low-wing airplanes?

I've been trying to figure this out using variety of manuals but still not found a satisfactory answer. Can somebody explain in detail?
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### 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?
184 views

### How calculated the drag coefficient lift coefficient with pressure coefficient?

I have got the Cp Plot on a wing, now I am trying to calculate Cl and Cd. And the angle of attack is 0 degrees, the wing has been split into N Panels, and the normal vector ni for every Panel is ...
26 views

### The lift and moment of the tail equations

We have The lift of the tail, $$L_t = C_L.q.S_t$$ The moment of the tail around c.g. $$M_(cg,t) = C_M.q.S.c$$ look at the S in the two equations. Why the lift of the tail is proportional to the ...
28 views

### How can we find maximum lift coefficient of Airfoil?

I am trying to find the maximum Lift coefficient for airfoil NACA 64A-404. I chose this airfoil for wing. I am stuck at finding the Clmax. I tried to use javafoil but javafoil is showing Cl less than ...
34 views

### Calculating Lift of a closed-wing drone

A group of students and I are designing a theoretical closed-wing drone and need to calculate lift based on the NASA lift equation. We've designed fixed-wing aircraft before and when it came to ...