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Aerodynamics: The real reason cars have ‘wings’
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F1 cars have aerodynamically sculpted bodies to maximise grip and performance.
PHOTO: REUTERS
Amrit Mirchandani Changaroth
Besides looking cool, what do the spoilers on the cars do?
Aerodynamics is the study of airflow over an object, and vehicle engineers and designers have spent decades trying to master it. Arguably, the most advanced form of aerodynamics on a vehicle is that of a Formula 1 race car.
On road cars, one might be able to notice aerodynamic wing elements (inaccurately referred to as “spoilers”) mounted high and to the rear of the vehicle. The wings are meant to create a phenomenon known as “downforce”, the opposite of “lift” as generated by an aircraft wing.
Downforce “presses” the vehicle into the ground for more tyre grip. In high-performance vehicles, the amount of downforce generated by aerodynamics can come up to half their weight to give them cornering stability and grip, rather than fuel efficiency or top speed.
Engineers design the wing elements of vehicles to extremely precise proportions. Aftermarket wings, which may give the car an aggressive look, can often be detrimental to high-speed balance and handling.
It is a costly affair to refine a car’s aerodynamics. As air cannot be seen, special rooms known as wind tunnels are built to properly understand this.
Typically, streams of coloured air are introduced to the front-end of scale models of the car.
Sensors are placed all around the room to collect air speed and air pressure data at multiple points around the vehicle.
However, aerodynamics is not lost on mass-produced vehicles. A correctly sculpted car will have a lower drag coefficient. This number shows how hard a vehicle has to work to move aside the air ahead of it. Thus, a higher drag coefficient number requires greater effort by the propulsion system to overcome this. A lower drag coefficient translates to better fuel efficiency.
An aerodynamic design is also good for comfort. In some cars, typically lower-end models, a high-pitched whistling sound can be heard when travelling at expressway speeds. This is due to turbulent airflow, which in turn increases the vehicle’s drag. Additional energy is required to overcome this, thus adding to increased consumption.
In electric vehicles, aerodynamics is a particularly important area of development as there are no engine noises to mask any unwelcome wind noise.
