Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page Visit Our Archives Ask A Question How To Ask A Question Question of the Week NEWTON Teachers Our Expert Scientists Volunteer at NEWTON! Referencing NEWTON Frequently Asked Questions About Ask A Scientist About NEWTON Education At Argonne Calculating Aspect Ratio of Wing

Name: Thomas
Status: student
Grade: 6-8
Location: CA
Country: USA
Date: Fall 2013


Question:
If the cord changes throughout the wing, than how do I calculate the aspect ratio?



Replies:
Thomas

I found this explanation at the URL: http://www.pilotfriend.com/training/flight_training/aero/aspect.htm

This article says: "aspect ratioAspect ratio is the wing span divided by the mean wing chord. An aircraft with a rectangular wing of area 12 m² might have a wing span of 8 m and wing chord of 1.5 m. In this case the aspect ratio is 5.33. If the span was 12 m and the chord 1 m then the aspect ratio would be 12. However because wings may have varied plan forms it is usual to calculate aspect ratio as:

Aspect ratio = wing span² / wing area "

You can get more information by reading the article at the above URL. By the way, I went to http://www.google.com and searched for " calculating airplane wing aspect ratio" and found a whole lot more interesting articles on this subject.

Sincere regards, Mike Stewart


Hi Thomas,

For wings that taper, the formula for aspect ratio is the wing span squared divided by the wing area. For the case of a constant chord wing, you can see this equation reduces to span divided by chord.

John C Strong


Thomas -

The aspect ratio is calculated using the MAC - Mean Aerodynamic Chord - the average chord of the wing. One way of getting the MAC is to take the area of the wing and divide it by the wing span.

Larry Krengel


Hi Thomas,

Because a typical wing chord (as you have stated) varies (or tapers) from root to tip, a wing's aspect ratio is measured by dividing the square of the wingspan, by the area of the wing as viewed from above.

Note that for a wing with no taper, the above calculation results in the same aspect ratio value that will occur by simply dividing the wingspan by the wing chord.

Regards, Bob Wilson.


Hi Thomas,

Thanks for the question. The simplest answer is to make several measurements. Each measurement should be evenly spaced along the wing. Then calculate the aspect ratio for each measurement. Then average the results. This procedure will provide an estimate. The exact procedure requires integral calculus--which you will learn in high school math or college math.

I hope this helps. Please let me know if you have more questions. Thanks Jeff Grell



Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 223
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: November 2011
Weclome To Newton

Argonne National Laboratory