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Air friction, or air drag, is an example of fluid friction. Unlike the standard model of surface friction, such friction forces are velocity dependent. The velocity dependence may be very complicated, and only special cases can be treated analytically.
Aerodynamic drag, sometimes called wind resistance, is an effect which a vehicle must overcome more and more as speed increases. Drag is a form of friction, though some of the air's effect on the vehicle is due to a low pressure zone behind the vehicle, and a high pressure zone in front.
20 Οκτ 2022 · Form drag, also known as pressure drag, is a significant component of aerodynamic drag in automotive design. It is caused by the motion of air around the vehicle, which leads to changes in air pressure. As the vehicle moves, the shape and frontal area of the vehicle cause the air to either compress or expand.
4 Μαρ 2017 · Therefore, engineers devised a non-dimensional number, called the drag coefficient (C D), which quantifies the aerodynamic sleekness of the vehicle configuration. The definition of the drag coefficient is: where D is the drag force, ρ is the air density, U is vehicle speed, and S is the frontal area. One of the nice aspects of this formula is ...
The air pressure would be causing drag if it were placed against the face of the object, friction would be acting along its sides, and potentially a relatively negative pressure would be acting on its back or suction.
The air that sticks to the surface of a car creates a drag force due to skin friction. Pressure drag is created when the shape of the surface changes abruptly, as at the point where the roof of an automobile ends. The drop from the roof increases the space through which the air stream flows.
The portion of the drag force that is due to the inertia of the fluid — the resistance that it has to being pushed aside — is called the pressure drag (or form drag or profile drag). This is usually what someone is referring to when they talk about drag.
