Gliders and FlightDavid Wagner

Part I: Wing Design

Basic Aircraft Geometry

Wingspan (b) Chord (c)

Wing Reference Area

Aspect Ratio

 

 

The 4 Forces of Flight

Lift

Weight

ThrustDrag

The Glider Technique: Gravity as Thrust

Velocity Vector(Where the Plane is

going)

Optimizing Glider Flight 

   

 

&

So,

Optimizing Glider Flight (cont’d)

 

 

Thus,

Optimizing the Aspect Ratio

 

Influence of Wingspan on Aspect Ratio

Wing Reference Area: 0.5m2

Effects of Wingspan and Aspect Ratio on Wing Design

Ideal Conditions:

- Small Chord- Large Wingspan

Part II: Stability and Egg Placement

Stability and Controlis the symbol for the centre of gravity of a body

ALL motion of an airplanecan be described as

combinations of yaw, pitch and roll about the CG,

Moments: The Seesaw Problem

Student 1

Weight: 600N

Student 2

Weight:300N

6m

6m

Without putting Student 1 on a crash diet, how wouldwe balance the seesaw?

Moments: The Seesaw Problem (cont’d)

Student 1Weight: 600N

Student 2Weight:300N

3m 6m

 

A “moment” is the tendency of a force to twist or rotate a body.

Applying Moments to Glider Stability and Egg Placement

Pos’n on CG Pos’n forward of CGPos’n aft of CG0.5m

0.5m

     

Optimizing the Position of the Egg for Stability

Close to the CG to minimize impactExtreme Cases:

Aft: Nose pitches up, aircraft stallsForward: Nose pitches down, aircraft nose dives

Thank you, and good luck!