# Coefficient of friction for air.

Discussion in 'Physics & Math' started by hosaf, Nov 28, 2011.

1. ### hosafRegistered Member

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Hello Everybody!

Do anyone know coefficient of friction for air.

I try to calculate distance of Fan.

I have some datas below

volumetric flow rate
mass flow rate
Air speed at exit of Fan
Fan Power

Thanks for help

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3. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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Go to google.com and type in "coefficient of friction for air".

edit to add: Welcome.

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5. ### prometheusviva voce!Registered Senior Member

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This thread is now the top result of that search.

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7. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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Well, well I guess that was my 15 nanoseconds of fame.

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8. ### hosafRegistered Member

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5
Ok. Thank you.

Actually I try to calculate air throw distance for Axial Fans for cold room applications. I know it's depend temprature, pressure, density or another things.

Do you have any idea, formula or documents about that???

9. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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10,676
I am not sure what you are trying to accomplish.

See if this link is any help.

10. ### hosafRegistered Member

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5
Thanks for help. But it is about fan selection.

11. ### prometheusviva voce!Registered Senior Member

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The best way to model the "friction" due to a fluid like air is to use drag, and specifically, the drag equation. Since how much drag you get depends, not only on the fluid, but on the shape of the object you have in the fluid, there are terms in the drag equation to account for that.

12. ### hosafRegistered Member

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5
Prometheus, I thank you for explanation and your links.

So you are right for drac cofficient but it generally about air on kind of shaeps.

I go on research if I find any solution, I'll share this topic.