1. PHYSICS CONCEPTS
AERODYNAMICS
Aerodynamics is a branch of dynamics concerned with studying the motion of air,
particularly when it interacts with a solid object. Understanding motion of air (often called a
flow field) around an object enables the calculation of forces and moments acting on the
object. Typical properties calculated for a flow field include velocity, pressure, density and
temperature as a function of spatial position and time. Aerodynamics allows the definition
and solution of equations for the conservation of mass, momentum, and energy in air.
The points to be kept in mind to minimize drag and to keep lift minimal are:
• Eliminating a low pressure area at the rear of the car
• To have a free airflow around the car without much obstructions.
• To have the front and rear aerofoils designed to cause least drag possible. Rather than
creating a zero angle tilt, research was done to find the optimum angle of tilt needed.
ZERO ANGLE TILT
To produce flow-deflection as well as the "circulation" required for lift, the trailing edge of
an airfoil must be fairly sharp. If we need a round leading edge and a sharp trailing edge,
then an airfoil must look like a streamlined teardrop shape. Zero angle tilt, ensures the
minimum possible drag due to the presence of the aerofoil. Any other angle would cause
either lift or down force. There are two ways to accomplish this deflection of air:
1. Tilt the entire airfoil at a positive angle of attack with respect to oncoming air.
2. Give the airfoil an arch shape, so it's curved upwards in the centre.
BERNOULLI EFFECT AND PRESSURE
Whenever the trailing edge of an airfoil causes air to move downwards, the air ahead of the
airfoil will move upwards, the air above the airfoil will speed up, and the air below the airfoil
will slow down. Each fast-moving parcel of air above the airfoil greatly outraces its
counterpart flowing below. Air divided by the airfoil doesn't rejoin again, instead a narrow
region of fast flowing air appears above the airfoil, and a wide region of slow air appears
below. Because of the "Bernoulli Effect," relatively fast air exerts less pressure than slow air.
This difference in pressure above and below the wing will create an upward force: the
"lifting force." End result: if we know the velocity of the air above and below the wing, then
we can calculate the difference in pressure and discover the value of lifting force.
FORCES ON THE CAR:
WEIGHT: A heavier car will have a slower race time as the car is propelled forward using
only a single burst canister. When a heavy car is launched, the initial thrust gets reduced fast
and the effect of opposing forces rise. But a heavier object will get decelerated slowly. Using
a lighter car will not only provide a significant increase in the initial thrust, but will also
cancel out the fast deceleration rate factor.
THRUST: Thrust is a reaction force imparted to push the car forward. When a system
expels or accelerates mass in one direction, the accelerated mass will cause a force of equal
magnitude but opposite direction on that system. This initial thrust is provided by a CO2
canister, that is pierced at the start of the race.
DRAG: In fluid dynamics, drag (sometimes called air resistance or fluid resistance) refers
to forces which act on a solid object in the direction of the relative fluid flow velocity.
Unlike other resistive forces, such as dry friction, which is nearly independent of velocity,

2. drag forces depend on velocity. Drag forces always decrease fluid velocity relative to the
solid object in the fluid's path. The force pushing against an object opposite to the direction
of travel in F1 in schools serves as the Drag.
Types of drag are generally divided into different categories. These are involved with F1 are:
a. Skin Friction
b. Interference Drag
c. Lift-induced drag
d. Wave Drag (aerodynamics)
* SKIN FRICTION (AIR RESISTANCE): As a solid object moves through air, a certain
amount of friction (called "skin friction") occurs between the surface and air, which tends to
slow the moving solid object. The resistance is the force opposing the movement of the
object at point of contact between the surface and air.
*LIFT : A fluid flowing past the surface of a body exerts surface force on it. Lift is the
component of this force that is perpendicular to the oncoming flow direction. It contrasts
with the drag force, which is the component of the surface force parallel to the flow
direction. This is the force pushing the object upwards whilst it moves.
*DOWNFORCE: It is the analogue of lift, pushing the car downwards whilst it moves.
Down-force is a downwards thrust created by the aerodynamic characteristics of a car. The
purpose of down-force is to allow a car to travel faster through a corner by increasing the
vertical force on the tires, thus creating more grip.
*ROLLING FRICTION: Force opposing the rolling of the wheels at the point of contact
with the track. Also the friction within the ball bearing based on points of contact within
races of the bearing.
*SURFACE AREA: Less surface area of the object reduces skin friction ,the total mass ,
and also a considerable amount of viscous air drag. The symmetry in the surface area of the
care ensures that equal amounts force is distributed at either side enabling the stable motion
of the car on the track.
USEFUL LINKS:
http://www.youtube.com/watch?v=bC8v6hlXnSk&feature=related
http://www.youtube.com/watch?v=jYaIXWNOa_A
http://www.youtube.com/watch?v=Ftj6A2P7lmw
http://www.youtube.com/watch?v=ooQ1F2jb10A&feature=related
http://www.youtube.com/watch?v=z2LsalyVq68&feature=relmfu
http://www.youtube.com/watch?v=Vjk9Ux2COx0&feature=related
http://www.youtube.com/watch?v=7jTeiz_f1iY&feature=related
http://www.youtube.com/watch?v=RgUtFm93Jfo&feature=related
http://www.youtube.com/watch?v=Ays6luaS4r0&feature=related
http://www.youtube.com/watch?v=5ltjFEei3AI&feature=related
http://www.youtube.com/watch?v=k7hTnkbmodI&feature=related