Finding Lift Force - Glider Wing

Click For Summary
SUMMARY

The discussion focuses on calculating the Lift Force (FL) of a glider wing using the equation FL=CL P A (v²/2). The user successfully determined the Lift Force to be 3.33 lbf and the mass of the aircraft to be 27.999 g. The critical missing variable, Velocity (V), was calculated using the energy derived from the elasticity of a rubber band launch, resulting in a horizontal velocity (VH) of 65.899 ft/s. The user provided a detailed breakdown of the calculations, including conversions from ft-lbf to suitable velocity units.

PREREQUISITES
  • Understanding of Lift Force and the Coefficient of Lift (CL)
  • Knowledge of fluid density, specifically air density
  • Familiarity with energy concepts, particularly elasticity
  • Proficiency in unit conversions, especially between imperial and metric systems
NEXT STEPS
  • Explore advanced aerodynamic principles related to Lift Force calculations
  • Learn about the effects of different Coefficients of Lift (CL) on glider performance
  • Investigate methods for measuring air density under varying conditions
  • Study the relationship between energy and velocity in projectile motion
USEFUL FOR

Aerospace engineering students, hobbyist glider builders, and anyone interested in the physics of flight dynamics and lift calculations.

aaronmorg
Messages
6
Reaction score
0
I am working on my semester project and have come across a hitch. I am trying to find the Lift Force of my wing using the following equation

FL=CL P A (v2/2)

Where:
FL is Lift Force
CL is Coefficient of Lift (I think)
P is the density of the fluid (Air)
A is the Area
V is Velocity

The only portion I cannot find is Velocity. I cannot, for the life of me, figured out Velocity when given force and mass.

I have a 3.33 lbf and a 27.999g aircraft.

Can someone please help me.

Equation so far:
FL=(.76764)(.076)(56.55)(V2/2)
 
Physics news on Phys.org
I found the equation for Horizontal Velocity. Here it is for anyone else who might be stuck in the same place.

VH=[tex]\sqrt{\frac{2E}{m}}[/tex]

E is energy
m is mass

In my case Energy was elasticity since my glider was flung from a rubber band. So I had to find ft-lbf, then use different conversion factors to get to a suitable velocity unit.

My work:

VH=[tex]\sqrt{\left[\frac{2(4.1625)ft-lbf}{27.999g}\right]\left[\frac{453.6g}{1 lbm}\right]\left[32.2\frac{lbm-ft}{lbf-s}\right]}[/tex]

Leaving me with Velocity in Ft/s

VH= 65.899 ft/s

Additional Information:

I was given a chart, from whence I figured that 15 in displacement gave 3.33 lbf, and converted to ft-lbf, giving me my E.
 
Last edited:

Similar threads

Replies
4
Views
6K
  • · Replies 5 ·
Replies
5
Views
6K
  • · Replies 1 ·
Replies
1
Views
11K
  • · Replies 1 ·
Replies
1
Views
25K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 24 ·
Replies
24
Views
7K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 23 ·
Replies
23
Views
3K