CO2 Dragster Design- Aerodynamics by ePn0RMft

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									CO2 Dragster Design


              Mr. Montague
                  2009
         Research and Development
                Objectives
Research in CO2 auto design involves the study
 of a few sciences related to the motion of your
 dragster.
• Aerodynamics- the study of how solid objects displace fluid
  air and other gases;
• Physics- the study of matter in motion;
• Tribology- the study of friction;
      Research and Development
             Objectives

Development of CO2 auto design requires-
• Understanding the problem or purpose- trying to achieve the
  fastest speed and/or best appearance;
• Knowing your limitations- being aware of safety regulations,
  materials allowed, specifications, tolerances and
  functionality;
• Making intelligent decisions- taking what you learn and using
  it to your best advantage;
• Testing your solution- comparing results with your
  classmates to see what works better;
         Research- Aerodynamics



 Air-
  – Is a type of fluid such as water that can be
    directed or displaced;
  – Has mass and is measured in terms of pressure;
  – Applies direct and frictional forces to objects in
    motion;
       Research- Aerodynamics
 Drag is a combination of two forces that will
  work against the acceleration of your CO2
  car.
  – Frontal Pressure occurs when tiny molecules of air hit the
    front of your car and is forced away to make room for
    other molecules to hit it.
  – Rear Suction occurs when an empty pocket of air is
    created in the back of your car resulting in a vacuum
    cleaner effect that tries to pull your car backward.
Air Flow
Rear Suction
      Research- Aerodynamics
 Lift is similar to rear suction in that a thin
  empty pocket occurs as air passes over a flat
  surface causing the car to lift.
 Down Force is due to high pressure in curved
  surfaces that causes the car to be pushed
  down. (Up next, notice how the windshield
  takes the shape of a spoiler.)
Air Flow
Lift
Down Force
Air Friction and Lift
        When a ball rotates in motion,
         it causes the air around it to
         flow with the rotation, often
         changing the direction with
         lift and down force. The
         location of the seams, speed,
         and spin all impact the
         airflow around the ball and
         thereby determine what the
         ball will do.
       Research- Aerodynamics
 Frontal Area is the total of all surfaces in the
  front of your vehicle which cause drag.
             Area = Length x Width
   Review Tips- Aerodynamics
 Avoid flat upright surfaces in the front of
  your car to reduce turbulence.
 Avoid flat upright surfaces in the back of
  your car to reduce rear suction.
 Shield as much air at the bottom of your car
  to maintain traction.
 Keep the surface area exposed to
  oncoming air to a minimum.
           Research- Physics


Force = Mass x Acceleration

Heavier objects require more effort to move at the
    same speed;
It is easier to push a CO2 car out of the ditch than to
    push an actual car out of the ditch.
          Research- Physics
How does the angle of your CO2 cartridge
 affect the efficiency of your car?
           Review Tips- Physics
 Avoid unnecessary extensions and ornaments that add
  weight to your car.
 The lighter you design your car, the more power will be
  used out of your CO2 cartridge.
 Make sure that your drill holes are straight and accurate to
  reduce extra forces acting on your car.
         Research- Tribology
Tribology is the study of friction between solid
  surfaces.
      Friction is a force that resists movement.
      Friction is found between moving parts and
       surfaces.




Where will you find friction forces acting on
 your car?
         Research- Triboloby
Does the paint job affect your car: Why or
 why not?
       Review Tips- Tribology
 Painting your car will reduce aerodynamic
  friction.
 Axel design is important to reducing friction.
 Lubrication of the axels can reduce friction.
 Less ground contact wheels have with the
  ground, the less friction will be present.
   Review Tips- Aerodynamics
 Avoid flat upright surfaces in the front of
  your car to reduce turbulence.
 Avoid flat upright surfaces in the back of
  your car to reduce rear suction.
 Shield as much air at the bottom of your car
  to maintain traction.
 Keep the surface area exposed to
  oncoming air to a minimum.
           Review Tips- Physics
 Avoid unnecessary extensions and ornaments that add
  weight to your car.
 The lighter you design your car, the more power will be
  used out of your CO2 cartridge.
 Make sure that your drill holes are straight and accurate to
  reduce extra forces acting on your car.
       Review Tips- Tribology
 Painting your car will reduce aerodynamic
  friction.
 Axel design is important to reducing friction.
 Lubrication of the axels can reduce friction.
 Less ground contact wheels have with the
  ground, the less friction will be present.

								
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