The technology of using fluid, either gaseous (pneumatics) or liquid (hydraulic), to apply force or to transport. Example of a simple form of a fluid technology system: Bicycle pump.
1. Each system contains a fluid, either liquid or gas, that moves through a system. 2. A pressure difference in the system creates force, which causes fluids to move or perform some special function like pushing a piston or opening or closing a valve.
States of matter Solids- Atoms tightly bound together, have a definite shape and volume. Liquids- atoms touch but have the ability to move has volume but no defined shape Gas- very low density have no defined volume or shape
Pneumatic Drive Systems Advantage Uses inexpensive compressed air to operate Good for clamping work pieces
Pneumatic Drive Systems Disadvantage Speed and position not easily controlled
Hydraulic Drive Systems Advantage Compact Allows for high levels of force and power, combined with accurate control Converts forces from a liquid into rotational or linear forces
Hydraulic Drive Systems Disadvantage –Messy. Fluid may contaminate parts, mess up other handling machines, and may not take a finish. –Not environmentally friendly – fluid can be toxic. –May require costly clean up and disposal.
Aerodynamics The study of the flow of fluid around solid objects of various shapes
4 basic principles of Aerodynamics A. Lift B. Thrust C. Weight D. Drag
Newton’s Second Law F = ma F = force m = mass a = acceleration For a fast car, you need: -Big force -Light car Speed = Distance / Time
Newton’s Third Law "For every action, there is an equal and opposite reaction.” Drag Thrust
Write the following in your journal
Problem You need to design the fastest car possible
Material One block of wood Two eye hooks Wheels & Axels
Constraints 1.) Car must have a CO2 chamber that is 1.5” deep and set ½” below top of block 2.) Car cannot be shorter in length than 5” 3.) Axles cannot be more than ¼” high 4.) Car must employ aerodynamic principles
Hint #1 The #1 most important factor in the speed of you dragster car is… Mass Cars with less mass go much faster!
Hint #2 Thanks to our friend gravity, everything has friction. Since we can’t eliminate friction, how can we reduce it?
Reducing Friction Make sure the axle & tires are free to rotate. Make sure the wheels are not rubbing on the car body. Be sure to install your eye-hooks properly. Poorly aligned eye-hooks are often the cause of a slow car.
Grading Your car will be graded on the following rubric Meets constraints _____ / 10 Evidence of planning_____ / 10 Time Trials_____ / 10 Alignment _____ / 10 Reflection questions_____ / 10