Aerodynamics is the study of forces and the resulting motion of objects through the air [source: NASA]. For several decades, cars have been designed with aerodynamics in mind, and carmakers have come up with a variety of innovations that make cutting through that "wall" of air easier and less of an impact on daily driving.
Essentially, having a car designed with airflow in mind means it has less difficulty accelerating and can achieve better fuel economy numbers because the engine doesn't have to work nearly as hard to push the car through the wall of air.
Engineers have developed several ways of doing this. For instance, more rounded designs and shapes on the exterior of the vehicle are crafted to channel air in a way so th­at it flows around the car with the least resistance possible. Some high-performance cars even have parts that move air smoothly across the underside of the car. Many also include a spoiler -- also known as a rear wing -- to keep the air from lifting the car's wheels and making it unstable at high speeds. Although, as you'll read later, most of the spoilers that you see on cars are simply for decoration more than anything else.

Drag: Drag is a force that tries to slow something down. It makes it hard for an object to move. It is harder to walk or run through water than through air.

Lift: Lift is the push that lets something move up. It is the force that is the opposite of weight.

Thrust: Thrust is the force that is the opposite of drag. Thrust is the push that moves something forward. For an aircraft to keep moving forward, it must have more thrust than drag.

Weight: Everything on Earth has weight. This force comes from gravity pulling down on objects.

Design Process
1 Week
Build Process
1 Week
Finish Process
3 Days
Racing
2 Day

CO2 DRAGSTER Design Specificaton
CO2 DRAGSTER

SITUATION
Each semester our class has a competition to design and produce a race vehicle powered by
a standard CO2 cartridge. Specifications of wheel size, body length, axle size and
cartridge position have been determined by the race organizers.
The vehicles will be raced against each other over a 20m distance with
tensioned fishing line to act as a guide. A ‘firing’ device will be used to
start the vehicles simultaneously.
If any car does not meet the specified requirements it will be disqualified from the competition.
The fastest vehicle wins.


BRIEF
Design a vehicle (to specs) to travel a distance of 20m in the fastest time possible using the power provided by a single standard CO2 cartridge.

DRAGSTER DETAILS MIN MAX PASSED REMEDY
a Axles (diameter) 3mm 4.5mm
b Axles (length) 35mm 88mm
c Axles bearing (diameter) 3.5mm 4.5mm
d Axle hole (diameter) 3mm 4.5mm
e Axle hole (position above body bottom) 5mm 10mm
f Axle hole (position from either end of body) 9mm 100mm
g Spacer bearing (diameter) (optional) 7mm 9mm
h Dragster body (length) 200mm 305mm
i Dragster body (height at rear with wheels) 75mm
j Dragster body (mass with wheels) 45g 170g
k Dragster body (width at axles - front & back) 35mm 42mm
l Power plant depth of hole 52mm 52mm
m Power plant housing thickness (around entire housing) 3mm
n Power plant housing (diameter) {Please use a 3/4” drill} 19.5mm 3/4”
o Power plant centre line (from body bottom) 31mm 35mm
p Screw eye (eyelet inside diameter) 4mm 8mm
q Screw eyes (2) or centre line of bottom, distance apart 155mm 270mm
r Wheels, front (diameter) 32mm 37mm
s Wheels, front (width at greatest diameter) 2mm 5mm
t Wheels, rear (diameter) 30mm 40mm
u Wheels, rear (width at greatest diameter) 15mm 18mm
v wheelbase 105mm 270mm

Students will race their cars in a brackets double elimination situation.

Students will develop a presentation on their design and race results to share with class.