How do aerodynamics improve?

Answer 1

It depends from object to object, and what you actually want from it.

The most simple example would be to stick your hand out of a car travelling at high speeds in two different shapes.

The first one, open your fists straight out (as though you were about to slap someone), and hold your hand straight out of the window so your palm is facing the direction in which the car is travelling. You will notice as the car's speed increased, it becomes more difficult to hold your hand out straight, i.e. you would need to apply more force to prevent your hand from flying back.

The second one is the same as the first, however this time your palm should face the surface of the road, thus having your hand horizontal, and you would notice that not much force is needed to keep the hand at its original position.

You learn two things from the above, one the larger the face of the body exposed to the stream of air, the more drag it would induce. The second, regardless of the size of the object, making the shape 'aerodynamic' would make the air to travel around the body more smoothly, thus giving it minimal resistance.

You would also notice your hand sort of lifting upwards in the second case. This is due to the lift force being generated by the shape you've made, which is also something looked into very much in aerodynamics.

PS: Don't stick your hand out of a moving car, especially at high speeds. It's hazardous. Well if you do, please be careful. :)

That would answer the frontal aspect of aerodynamics the other area is drag created by a vacuum in the rear. The air pocket would need to close by the shape of the rear of the vehicle to lessen the effect of drag resulting in poor gas mileage and instability of the rear end of a car. you would best explain drag by the effect of an eighteen wheeler going down the road creating a vacuum behind it. Some vehicle use a rear spiler to force the direction of air to help lower the rear of a car for better control overcoming the effects of lift (air under the car. Expensive cars tuck in the undercarriage and exhaust sytem of the car and to allow smoother air underneath the car for noise reduction, mileage control and improved handeling, while the highest of automobiles cover the entire undercarriage with a panel.