How Does Air Control Race Cars?

(Gears Engaged)

Imagine a body moving in water. Imagine the force which the body requires to tear apart the layers of the water in order to move. The case is similar with a car. The only difference is that the car has to cruise in air rather than water. The car also has to pierce the layers of air in order to move forward and overcome the drag forces offered by the air. Though we can never reduce this drag force to zero but we can decrease it to a great extent by doing certain changes in the design like minimising frontal area (area seen from the front), decreasing the rate of increase of frontal area, filleting the corners, covering the wheels by sparts (as the rotating wheels are a great source of turbulence) etc.

As technology evolved, Engineers not only found ways to minimize this drag but also used this problem as an advantage which allows light race cars to cruise at high speeds i.e. around 200 miles/hour and even take corners at such speeds. The same force which is used to lift an airplane upwards is now used in race cars and is known as the downforce which pushes the car down causing it to stick to the ground. This down force is so strong that it can make the car stick to the surface even if the car is made to run upside down. The science behind this fact is  the flow of the air around the car, more precisely flow above and beneath the car and simple application of Bernoulli’s theorem. The designed aerodynamics of the car cause the air beneath the car to move with much more velocity as compared to the air above the car, which by Bernoulli’s theorem causes more pressure towards the ground.

The Formula One racing cars are built to generate as much downforce as possible. At speeds at which they travel, and with their extremely light weight, these cars actually begin to experience lift at some speeds. Physics forces them to take off like an airplane. Obviously, cars aren't intended to fly through the air, and if a car goes airborne it could mean a devastating crash. For this reason, downforce must be maximized to keep the car on the ground at high speeds. Formula One cars achieve this by using wings and spoilers in front and rear of the vehicle. These aerodynamic parts make the air flow in such a way that the air presses the car to the ground and allows the car to maintain high cruising speeds.

Aerodynamics of race cars has changed the dimensions of racing. Race companies are spending more and more on the research and study of the aerodynamics of race cars as a little better aerodynamics provide the winning edge over others.

- Machinist