A Beginner’s Guide to Aerodynamic Design
This month we’ve been getting more than a little excited about the Bloodhound SSC – a SuperSonic Car that has become the focus of a recent exhibition in the Royal Cornwall Museum – and thinking about that car’s beauty and style has also got us thinking about some of the design principles that make it all possible.
One of the most crucial design elements, and something which every engineer should know about (especially those involved in car manufacturing!), aerodynamics means everything that relates to the study of what happens when air hits a solid object and, of course it’s practical application.
And, while we’ve been thinking about it in terms of vehicles lately, it’s actually a crucial element of many items that we see or use each and every day. From wind turbines to bridges, and even the planning for how to lay out entire towns, aerodynamics plays such a vital part in day-to-day life, we thought it was worth putting together a guide laying out the basic principles for those of you who work in other areas to get to grips with
While they might not have been discussed as such, the basic principles behind aerodynamics have been known for 1000s of years; key principles such as drag (which we’ll get to in just a moment) would have been needed to power objects such as sailboats and windmills in ancient civilizations, while specific information relating to them appear in the work of writers such as Aristotle (384-322 B.C.).
As early as the 17th Century, aerodynamics began to take shape as the modern discipline that scientists and engineers make use of today. Thanks to brilliant minds such as Sir Isaac Newton and Charles Renard, ideas surrounding aerodynamics have developed over time to become the set of knowledge that we are able to utilise now.
As we mentioned earlier, the basic principle of aerodynamics is to work out how an object, such as the wing of a plane, will interact with the air. Essentially, this allows you to consider the forces that will impact the movement of the object, and consider how to limit or enhance them.
One which you’ll almost certainly be familiar with is drag, a force which acts in opposition to the relative motion of an object which is to say, it tries to stop you from moving. A lot of drag can cause turbulence, which has a negative impact on the stability of a vehicle, so designers need to take this into account by making vehicles as streamlined as possible. This will also mean that the vehicle needs less fuel to get up to speed, making it great for conserving energy and helping the environment.
The other important force to know about is lift, which can be calculated by working out the velocity of the air. For something like an aeroplane’s wing or a boat, higher velocity will make for lower pressure – and this is what allows for lift. For a design team, understanding these forces and the relevant equations ensures that a finished product will be faster, more efficient and more stable.
The uses of aerodynamics that we’ve listed above play an active part in our lives every single day. For instance, aerodynamic clothing allows cyclists themselves to become more streamlined, giving them increased speed. Even better, the way that the air moves over the cyclist means that there will be less drag when it hits the person behind, allowing them to hit quicker speeds with their bike too.
Exactly the same principle also applies to motorsports, allowing the 2nd place vehicle to benefit from the clean air that passes over the lead car. This means that coming up behind a 1st place car as a racing driver can give you the boost needed to accelerated into the lead position.
There’s so much more that we could tell you about the fascinating science of aerodynamics, but hopefully this info has been enough to get you interested!