Egg-0-Naut

1
Egg-0-Naut
2
Instructor Info

• Andrew Roberts
• ajrober4_at_gmail.com
• 7 year participant in Science Olympiad
• Multi event medal winner at regional at state
  tournaments
• Coached State Champions in Wright Stuff
• 4 year SO Summer Camp Instructor
• Science Olympiad student intern

3
Process

• Read and understand the rules
• Research
• Design
• Build
• Test
• Analyze
• Fix

4
Important Rules

• Build up to 2 rockets before the tournament that
  carry a grade A egg
• MUST WEAR SAFTRY GLASSES
• Nothing within 5 cm of the nozzle
• Can use any recovery system

5
Important Rules

• Rockets will use 2 liter soda bottles
• Launched at 75 psi
• Best single rocket time will win
• Will receive extra 15 seconds if egg doesnt
  break extra 3 seconds if egg detaches from
  pressure chamber

6
What makes it work?

• Water is poured into the pressure chamber
• Air is then pumped into the bottle.
• When the rocket is released, the air forces the
  water out of the bottle.
• Newtons Third Law of Motion kicks in

7
Parts of the Rocket and Forces
8
Pressure Chamber

• 2 Litter soda bottle
• Do not cut or scratch the pressure chamber.
• Can glue fins to pressure chamber with silicone
  or polyurethane glues.
• If pressure chamber is damaged it will not be
  launched

9
Fins

• Fins keep the rocket stable in flight
• There must be at least 3
• Fins must be ridged
• Backswept fins work best

10
Fin Shapes
11
What does it mean to be stable?

• Stability the tendency of the rocket to return
  to equilibrium
• This means if the rocket begins to veer, it will
  straighten back up on its own.
• To be stable, the center of mass must be closer
  to the top of the rocket than the center of
  pressure

12
Nose Cones

• Popular types
• Conical
• Blunted Conical
• Elliptical
• Spherical
• Nose cones reduce drag
• Conical are easy to make but can be difficult to
  get straight.

13
Recovery Systems

• A recovery system is something that slows the
  rockets decent.
• The two most popular at the parachute and the
  back-slider

14
Recovery Systems

• The velocity of a falling object can be shown as
  follows
• where v(t) is velocity, g is acceleration do to
  gravity, c is the coefficient of air resistance,
  t is time, and v(0) is initial velocity.
• C is much larger for a parachute than a
  backslider therefore, it will fall much more
  slowly

15
Parachute

• Parachutes work best but are harder to get to
  work consistently
• The size needs to match the rocket.
• It should have 8 to 10 strings
• Fold it like an accordion and then wrap extra
  string around it to keep it folded

16
Making a Parachute
Cut Here
17
Making a Parachute
18
Backslider

• Backslider is made by making the center of
  gravity close to the center of pressure
• This prevents the rocket from turning over at
  apogee and instead floating down on its side.
• Fins on this type of rocket should be larger to
  help slow it down.

19
Example Backslider
20
Examples