Whether it is an airplane wing or sail of a sailboat calculating the lift can be done in the same way
We assume that the weight force of the aircraft is 2100 N.
we are seeking:
- a lift force balancing the weight of our aircraft: 2100 N=lift = weight
To do this we can act on:
-the angle of incidence(attack) of the wing
-the length of the wing
With standard mecaflux
- -Select a profile with drag and lift. We use for our wing profile BE50. (Polar patterns are already set in mecaflux but you can change the Cd and CL.
- - Enter the parameters of the fluid-speed: 10 knots, temperature 20 ° C, density air (1.225 kg/m3)
- - Enter the profile chord (the width of the wing, take 4 meter)
- - Enter the length of the wing (say 10 meters)
- - the angle of incidence(attack) of the wing (try 10.5 °. Incidence proposed values are those studied in wind tunnels. they are limited to the interesting angles, beyond the profile is stalling)
- - Click to calculate
The diagram shows the profile BE50 after calculating the value of 782 Newton lift with 10 knots of wind ,we seek to balance a weight of 2100 N our lift is too low
- Change the profile chord (the width of the wing, take 6 meters)
- Change the length of the wing (say 18 meters)
- Click to calculate
the lift force for b50 is 2112 Newton (215 kgf) with 10 knots of speed.
We will therefore have a wing of 18 meters for lifting our plane with a speed of 10 knots...
let's see with a speed of 30 knots:
- Change the parameters of the fluid-speed: 30 knots, temperature 20 ° C, density air (1.225 kg/m3)
- 18 m in length is kept
- 6 m width is kept (chord)
- Click to calculate
the lift force for b50 is 19013 Newton (1939 kgf) with 30 knots of speed.
19013/2112 = 9 times more lift with three times the speed, Lift evolves with the square of the speed!:
in fact we see, by changing the length and width of the profile, as a wing with 6 meters long and 2 meters wide with 30 knots of speed we have enough lift for our plane to take off.
Warning: loss of lift at the wing tips are not considered.
For a wing with a length of 10 and a width of 1 count about 15% loss of lift compared to the results given by MECAFLUX.
For a wing with a length of 10 and a width of 5 count about 30% loss of lift compared to the results given by MECAFLUX.software for propeller and wings calculation that integrates the effects of losses at wing tip and set the twist of the wing
Heliciel has its own 3D modeling engine to wing, and a large database of aerodynamic or hydrodynamic profiles and export 3D function (igs format) that allows rapid achievements models.
Modeling wings or foils in heliciel
Modeling a wing mast sailing in heliciel
(The calculation of the wings allows a pre-dimensioning but tests must always be carried out by experimentation without endangering the safety of persons!)