Airplane Dihedrals

By Mazey Rix

Scienentific Method

Question:

What affects does the wing dihedral have on the flying qualities of an airplane?

Hypothesis:

If you have positive dihedral, the airplane will be more stable until a certain point when the wing stops creating lift.

Reasearch: I am going to just be looking at four types of wing dihedrals:

What is a dihedral?- the angle that the wing is tilted


positive dihedral- very stable but not as much lift. Most planes have a positive dihedral.


neutral dihedral-some lift and is somewhat stable. If you start tipping, you keep tipping unless you change it and bring it back to its regular position.


anhedral wing (also known reverse dihedral or negative dihedral)- lots of lift but not stable. Some fighter jets have an anhedral wing, because this helps them roll faster. Naturally the plane wants to flip over.

Here are some different dihedral designs:

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Real Life Examples

My experiment and the steps I took:

Design of experiment-test four different airplanes with four different dihedrals- lots of dihedral, some dihedral, no dihedral, and negative dihedral.


Independent variable (change)- the different dihedrals on the airplanes

Dependent variable (results)- how far and well the airplane flies

Constant variable (same)- I throw it the same way, measure the same, and twist the rubberband the same amount.

Control group- no dihedral (flat)



What am I testing-the length the airplane flies and the flying qualities


procedure-

-research background information

-build airplanes

-test the balance and weight of airplanes

-test track

-practice runs

-begin testing (1,2,3,qualities,video)

-collect data

-evaluate data

-conclusions

- transfer into smore

My experiment Results:

Data Table

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Graph

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Conclusion:

Looking at the different results, you can tell that my hypothesis was correct and plane 2 worked the best and flew the farthest. It was very stable, and still created lift. Plane 1 didn't create as much lift, even though it was very stable, so it fell to the ground quickly. Plane 3 worked well and created lots of lift, but it was not very stable, so if it started tipping, it would keep tipping and eventually fall, because it didn't naturally correct itself. Plane 4 was not stable at all. It was always trying to correct itself by flipping over, but this caused it to crash to the gound. So in conclusion, Plane 2 definitely worked the best!
Mazey airplane 1 - large positive dihedral
Mazey airplane 2 - moderate positive dihedral
Mazey airplane 3 - no dihedral
Mazey airplane 4 - negative dihedral

Information Cited- Mathew Boyd Rix