Shoebox Design Challenge No Extras

Fly the Dream!Fly the Dream!

The Four Forces of Flight

Review - Gliders

• Have No Powered Thrust

• Typically have a LONG wing span

• Usually very LIGHT

• Built to Reduce Drag

What can we Control on our Gliders?

• Mass

• Placement of wings for MAXIUM LIFT

• Angle of Wing

• Aerodynamic to REDUCE Drag

How Do We Control Lift?

• Bernoulli's Principle• Angle of Wing

http://www.grc.nasa.gov/WWW/K-12/airplane/foil2.html

Bernoulli's Principle

• Bernoulli's Principle states - as the velocity (speed) of a fluid (air) increases, the pressure exerted by that fluid (air) decreases.

Airplanes get a part of their lift by taking advantage of Bernoulli's principle. Race cars employ Bernoulli's principle to keep their rear wheels on the ground while traveling at high speeds.

• If wings were flat– Air would travel from front of the wing - back of the wing

covering the same distance over the same time

• However - Wings are Curved on top– So the air takes longer to travel over the top of wing to catch up

with the air moving under the wing

• Faster air on Top / Slower air on Bottom

Bernoulli's Principle

• Bernoulli's Principle– Air on top is moving so FAST it can NOT add

pressure (LESS / LOW AIR Pressure)– Air on bottom is moving SLOWER so it adds

pressure (MORE / HIGH Pressure)

• Lower Pressure on TOP and

High Pressure on BOTTOM creates LIFT

Bernoulli's Principle

• Activities– Funnel and Ball– Umbrella Bag

How Do We Control Lift?

• Bernoulli's Principle• Angle of Wing

http://www.grc.nasa.gov/WWW/K-12/airplane/foil2.html

Angle of Wing

How do we Control Drag?

• Which is more aerodynamic?– A Hummer or a

NASC Car

How do we Control Drag?

• How about between Tony Stewart and Dale Earnhardt Jr.

• NASA wants to know the subtle differences

Testing Drag

• NASA can use either a Wind Tunnel or Fluid Dynamic Lab to understand the aerodynamics of a plane– Wind tunnels use wind

to match “real time” velocity and speed

– Fluid Dynamic Labs use water moving at a slow speeds

Shape

WeightBalance

Shoe Box has to remain INTACT Four (4) Sides and bottom

Can slit sides of box to insert wings

NO PROPELLERS – Nothing to add power or thrust

Can use any kind of material you want(duck tape, news paper, yard sticks, etc) And of Course – A Shoe Box

- Glide Slope RatioDistance / Height Thrown

- Aspect RatioLength of wing / Width of wing

- Higher the number the better the design

T.K.Witherspoon@nasa.gov