What causes rotational motion and condensation on the wings of sprint cars?

In summary, the conversation discusses the formation of condensation vortices behind the wings of sprint cars on asphalt tracks. It is caused by a drop in pressure and temperature, and can be seen on the underside of the wing. The rotational motion of the vortices can be observed, and it is compared to contrails formed by airplanes. The angle of attack on a sprint car's wing is higher than that of an airplane, and the formation of the condensation is similar to that seen on the trailing edge of an airplane wing during takeoff.
  • #1
c_huchel
3
0
I used to race with a club called NSRA (www.nsraracing.com) that runs winged sprint cars on asphalt tracks. Every once in a while, especially on the larger tracks and in colder weather, you'd see little condensation vortices (plural vortex) behind the tips of the wings. Even less often one could see a "pocket" of condensation just below the trailing edge of the wing. It kind of looks like a cloud, in a way. What causes that? Is it related to the vortices? I'd like to get pictures, but it happens so abruptly, and usually at night (not camera friendly, when the air is around 40-50 degrees farenheit).
 
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  • #2
is it kind of like when an airplane is flying?
[?]
 
  • #3
Its probably a contrail exactly like one created by a plane.
 
  • #4
I suppose it's a contrail, but it's not exactly a trail. I guess it's more like a block of low pressure (sounds like a weather system). I'll see if I can find pictures of the contrails and post them to my site.
 
  • #5
Yes, it is caused by the drop in pressure, but I've recently been doing a little research which would seem to indicate that this is only the indirect cause. According to everything I've read, air kept at a constant temperature and volume will hold the same amount of water vapor regardless of pressure. So I think this must mean that the drop in pressure causes a drop in temperature, and the drop in temperature is what causes the condensation.

Although con trails from aircraft can be formed this way, it is rather rare. Usually, when you see a contrail behind an airplane, the cloud is being caused more by the water clinging to the exhaust than by the change in pressure. But if you've evr seen an airshow, you can see that the wings do indeed form little "clouds", which appear to cling to the wing's surface.

Since you spoke of vortices, I'm assuming you've actually seen rotational motion to some of these clouds. Would I be correct in my supposition that this rotation is outward at the top, inward at the bottom? And does the cloud from the "block of low pressure" form on the underside of the car's wing?
 
  • #6
Originally posted by LURCH
Since you spoke of vortices, I'm assuming you've actually seen rotational motion to some of these clouds. Would I be correct in my supposition that this rotation is outward at the top, inward at the bottom? And does the cloud from the "block of low pressure" form on the underside of the car's wing? [/B]
There is a rotation. If I remember correctly, viewed from the rear, the left side rotates counter-clockwise, and the right rotates cloclwise. The cloud forms on the underside of the wing, where it seems the air is moving the fastest. The angle of attack on the wing of a sprint car is relatively high compared to an airplane wing. I have seen the condensation on the trailing edge of an airplane as it was taking off. The best view of it from an airliner is right behind the wing. You also get to watch the flaps, spoilers and airbrakes work, which is a marvel of physics if you ask me.
 

Related to What causes rotational motion and condensation on the wings of sprint cars?

1. What are condensation trails and how are they formed?

Condensation trails, also known as contrails, are long, thin, white lines that form behind airplanes as they fly at high altitudes. They are created when hot engine exhaust mixes with cold air and the water vapor in the exhaust condenses into tiny ice crystals. These ice crystals form the white streaks we see in the sky.

2. Are all condensation trails the same?

No, not all condensation trails are the same. The length, thickness, and persistence of a contrail depends on factors such as the temperature and humidity of the air at high altitudes, the type of engine and fuel used, and the speed and altitude of the airplane. Some contrails may dissipate quickly, while others may linger in the sky for hours.

3. Do condensation trails contribute to climate change?

There is ongoing debate among scientists about the impact of contrails on the Earth's climate. Some studies suggest that contrails can trap heat in the Earth's atmosphere and contribute to global warming, while others argue that contrails can also reflect sunlight and have a cooling effect. More research is needed to fully understand the impact of contrails on the Earth's climate.

4. Can condensation trails affect air quality?

Yes, condensation trails can affect air quality. They can contribute to the formation of cirrus clouds, which can trap pollutants and affect air quality. However, the overall impact of contrails on air quality is still being studied and is considered to be minimal compared to other sources of air pollution.

5. Is there any way to prevent or reduce the formation of condensation trails?

There are some techniques that can be used to reduce the formation of contrails, such as flying at lower altitudes or using different types of fuel. However, these solutions may not be feasible for all airplanes and can also have other negative impacts, such as increased fuel consumption. More research is needed to find effective ways to reduce the formation of contrails without causing other problems.

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