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Aerodynamic Design In Cars

Aerodynamics implies the study of motion of air when it interacts with a moving object. Why do we need this? Because when we know how the aerodynamics is playing a part when the object is in motion only then we can see the various forces that may be helping or restricting the motion of the vehicle. This concept was known to scientists long back and was eventually applied to cars by the 1950s. The automotive engineers were now sure of the detrimental effects of ignoring the aerodynamic drag on the efficiency and speed of the car.

The concept of aerodynamics came into picture with the advent of automobile racing. Particularly the Indianapolis 500. The cars were made in a streamlined shape to give them the least amount of drag while racing. But at that time, apart from the streamlined shape there was not much research into the field. More emphasis was laid on the engine, chassis suspension etc. But around the 1960s, aerodynamics was recognised as one of the major factors which influenced how the cars were designed. During this time, there were a lot of restrictions on the engine capacity and power so aerodynamics came to the rescue of engineers who wanted the car to run at greater speeds without altering anything in the engine.

Few terms are commonly heard today when car manufacturers (especially the ones manufacturing racing cars) describe how aerodynamically smooth their cars are:

- Drag Coefficient

This is associated with the surface area of the car. Specifically, the frontal area of the car. This should be as low as possible. A low value indicates that the car will have least aerodynamic drag and thus will be able to move more efficiently at higher speeds.

- Downforce

Whenever a vehicle moves at a fast speed there is some "lift" created. As the speed increases so does the lift. This tends to decrease the speed of the car. So, all car manufacturers, may they be racing car manufacturers or manufacturers for racing cars tend to make sure that the downforce is as much as possible. Measured by a term known as lift coefficient, this values ranges around 0.3 in a family sedan whereas this value for a race car may be as low as -3.0 . So you get a fair idea of how important this factor is. This also improves cornering at high speeds since the car does not experience any lift and is more stable on the road.

These days aerodynamics is an important factor in every manufacturer's design since it helps to accomplish much more than just high speeds. Wind noise and even efficiency of an engine is greatly increased by smooth aerodynamics. Apart from this, the driver will also feel more confident on the road since the vehicle will be completely under his control.

The main technique used by design engineers to test the aerodynamics are Wind Tunnels. This provides the design team with an approximate idea of how their design is going to be affected by wind. Flow visualization can be seen and can help the design engineers make their designs more aerodynamic than before.

Aerodynamics, thus plays a very important role in the design of a vehicle. This can be seen in the attitudes of the manufacturers as well, be it Audi's A8 or Smart, every car these days is streamlined for optimum aerodynamics.