Timeline for Will an air-filled tire normally gravitate toward being nitrogen-filled just by refilling with air?
Current License: CC BY-SA 2.5
16 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 17, 2020 at 21:48 | answer | added | John Darby | timeline score: 0 | |
| Jan 11, 2013 at 5:26 | answer | added | xpda | timeline score: 1 | |
| Dec 30, 2010 at 22:12 | comment | added | Evan Carroll | @Greg P: Nitrogen in tired used on road thing, but yea car thing. | |
| Dec 30, 2010 at 22:04 | comment | added | Greg P | @Evan: ? Is this a car thing? | |
| Dec 30, 2010 at 20:51 | answer | added | Omega Centauri | timeline score: 2 | |
| Dec 30, 2010 at 20:23 | answer | added | user68 | timeline score: 6 | |
| Dec 30, 2010 at 17:33 | comment | added | Greg P | It is true that pure nitrogen would have a different viscosity than air, meaning that the rate of leakage through small defects would be different. But seriously folks... | |
| Dec 30, 2010 at 17:30 | comment | added | Greg P | @J.M. Then I think it is likely that this whole nitrogen-tire thing is bogus. Because the 'windows' (gaps in a crosslinked polymer melt) are so large that we can still model the leakage using hydrodynamics of bulk air (oxygen, nitrogen, everything). The difference between atom sizes seems irrelevant. | |
| Dec 30, 2010 at 17:27 | comment | added | Evan Carroll | I smell mythbusters. | |
| Dec 30, 2010 at 17:25 | comment | added | user172 | @Greg: exactly. Rubber only becomes "crystalline" if you stretch it (how much of a stretch depends on the rubber); at the normal conditions of a tire, you'll have "windows" for air to seep in/out. | |
| Dec 30, 2010 at 17:21 | comment | added | Greg P | @J.M. The question is really what is meant by "diffuses." Is it a molecular diffusion process (like air diffusing through water) or a process that can be modelled by tiny currents of air moving through 'cracks'? These are very different possibilities. Note that even rubber that is 'perfect' from an engineering standpoint will have 'defects' from a physicist's standpoint (i.e. rubber is nothing at all like a perfect crystal). | |
| Dec 30, 2010 at 17:15 | comment | added | user172 | @endolith: it diffuses out. The question now is how porous is the rubber? Cracks and other such imperfections will of course accelerate the seeping out. | |
| Dec 30, 2010 at 17:06 | comment | added | endolith | More general question: How does air escape from tires or balloons? | |
| Dec 30, 2010 at 16:51 | comment | added | Greg P | The idea that nitrogen stays in the tire longer seems crazy to me. Particularly if the mechanism of leakage is 'small' leaks or valve defects, on the scale of atoms these are still gigantic features. See also: straightdope.com/columns/read/2694/… | |
| Dec 30, 2010 at 16:38 | history | edited | Evan Carroll | CC BY-SA 2.5 |
edited title
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| Dec 30, 2010 at 16:30 | history | asked | Evan Carroll | CC BY-SA 2.5 |