How Do You Calculate the Area of an Airfoil Cross-Section?

Click For Summary
To calculate the area of an airfoil cross-section, the integral ∫(f(x)-g(x)) dx from 0 to 1 is suggested, but identifying the functions f(x) and g(x) is challenging. The discussion emphasizes the importance of the neutral axis and suggests finding x as a function of y to calculate the second moment of area. Additionally, determining the mean aerodynamic chord (MAC) is recommended for future aerodynamic calculations. Historical context highlights that aircraft engineers borrowed terminology and techniques from boat building, which aids in understanding wing geometry. Accurate calculations are crucial for effective wing design and analysis.
Alec Trujillo
Messages
1
Reaction score
0
New poster has been reminded to post schoolwork in the Homework Help forums and use the Template
Not really sure if this thread belongs here but I am supposed to figure out the radius of gyration, section modulus, and Q values at the neutral axis for this symmetric wing cross section. The only problem is that I am not even really sure how to find the area of the cross section. i know that it'll be ∫(f(x)-g(x)) dx from 0-1 (pretty much the only hint that we are given is that the cross section can "fit perfectly in a 1in x 1in box) but how i even find f(x) and g(x) is beyond me.
 

Attachments

  • Screen Shot 2018-07-23 at 12.08.23 AM.png
    Screen Shot 2018-07-23 at 12.08.23 AM.png
    6.6 KB · Views: 1,781
Physics news on Phys.org
Poster has been reminded to watch for misplaced homework threads, and not to do the student's homework for them.
There is a high chance for my answer to be wrong.If its right, by solving the equatuon with the boundary condition will give you the curve(refer the image).
If X axis in the diagram is your neutral axis then it is better to find x as a function of y by using the same boundary condition.(To calculate 2nd moment of area about the x axis).
IMG_20180725_102204.jpg
 

Attachments

  • IMG_20180725_102204.jpg
    IMG_20180725_102204.jpg
    21.6 KB · Views: 1,808
Last edited:
Alec, for future aerodynamic calculations consider determining the mean aerodynamic chord (MAC) of the wing section under study.
https://en.wikipedia.org/wiki/Chord_(aeronautics)

Before digital computers became common, aircraft engineers adopted many terms and techniques from boat building including chords.
Determining appropriate chords often simplifies moment calculations and may help your understanding of wing geometry.

--Norm
 

Similar threads

  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 3 ·
Replies
3
Views
618
  • · Replies 2 ·
Replies
2
Views
732
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 7 ·
Replies
7
Views
7K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K