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Air air air

Air air air

Air air air

I am working on a project involving car aerodynamics and I am an EE, so this is a bit off from my field. Does anyone know the name of the wind displaced by a vehicle in motion? Like the air blown on a wind tunnel but in real life?
I have tried to google it but I get ambiguous results.
Thanks for the help!


RE: Air air air

Slipstream perhaps or draft.

RE: Air air air


- Steve

RE: Air air air

It's still air, until the vehicle nears, then it's displaced laterally to the vehicle's path, and returns to more or less its initial state some time after the vehicle passes.
Not like in a wind tunnel.

There's a similar dichotomy with water:
In river rapids, the waves are stationary but the water moves.
In ocean surf, the water is more or less stationary, but the waves move.

Mike Halloran
Pembroke Pines, FL, USA

RE: Air air air

Slipstream as mentioned above

RE: Air air air


First of all, even though you are an EE, you might want to get the terminology correct. A car body moving through the air does not "displace wind". Instead, the moving car body imparts momentum to the static air mass as they come into contact. This results in a transfer of energy from the vehicle to the air mass. The net transfer of energy from the car body to the air mass is known as "drag".

As MikeHalloran points out, there is a huge difference between the energy required to pump air at 60mph past a car body in a 100% scale wind tunnel, versus the energy required to drive that same car at 60mph through still air.

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