By: Grattan R.
When most people think of airflow on a car they think
of the car’s exterior and how it looks. While the exterior of a car is
extremely important to how the car cuts the air and cools itself, the interior,
or what is behind the panels has plenty to do with the cooling of a car. To put
it in perspective, when a Bugatti Veryon is moving at 250mph, it has 10000lbs
of air pressure surging into vents on the car that go into 10 radiators and to
cool the engine. This drastically helps in cooling the engine, but what about
when the car is stopped? If the car just went 250mph, chances are it’s 16-cylinder
engine is expelling gasses that are close to 1000 degrees, and while 10
radiators may be excessive, it still isn’t enough alone to kill the heat. That
is a different story, and the challenge of the under-the-hood part of
aerodynamics. 
While just keeping an engine cool is the main part of
aerodynamics, 2 aspects of heat are lost when considering cars: brake
temperature, and power lost from heat. First for brakes, the essential stopping
force for cars. What happens if the brakes on a car get too hot and seize?
Taking the Veyron for example again, it produces one ton of stopping power if
the brakes are slammed completely to the floor, and at that point the brake
rotors will be at about 1800 degrees. At this point the discs will be glowing
red-hot, producing a very distinct smell, and will likely be producing smoke.
In order to keep the brake rotors cool enough, vents are placed under the car,
in front of the wheels, and behind the wheels. These vents provide massive airflow
to the brakes in addition some sports car companies or racing teams will
directly route air to the brake disc surface with a vacuum tube.
The second aspect, power lost from heat, is not as
much of a safety issue as brakes, but still important for those trying to make
power. Yet again, for example the Bugatti Veyron loses about 2000hp to heat, so
in reality it makes closer to 3000hp. The more heat you can eliminate from an
engine, the more efficient it can be. It is the same as when a car is faster on
a cold winter day than a hot summer day, the colder air can create a larger
explosion in the combustion chamber, and the colder air overall keeps the
engine cooler. A side effect of combustion engines is heat, and just like
cellular respiration, a side effect is heat, so in comparison, both cells and
engines are not as efficient as they could be because of heat. If the loss of
heat could be eliminated from an engine’s combustion cycle, that lost heat
would instead be replaced by a larger explosion from the gasoline, spark, and
air combination in the combustion chamber.
It is evident that cooling is important to a car in a
deeper sense than just keeping the engine from overheating, losing power, or keeping
the brakes at a safe temperature. From the methods listed above, which do you
think is most important to a sports or race car?
Works
Cited
Okulski,
Travis. “Airflow Is Even More Important to a Car Than You Think”. Road&Track.com. Hearst Digital
Media. Web. 26 February 2016.
Picture Sources
No comments:
Post a Comment