January 16, 2009

Kinematic Viscosity of air Vs Temperature

This is similar to my previous post on the property correlation of a fluid to use it in calculations making results better & life simpler.

This time I am putting the formula for calculating the Kinematic Viscosity of air vs temperature.

The correlation is as below.

kv = -1.1555 x 10^(-14) x T^3 9.5728 x 10^(-11) x T^2 + 3.7604 x 10^(-8) x T - 3.4484 x 10^(-6)

Where

kv is kinematic viscosity in M2/sec
T is in K

The above equation is valid from T = 100 to 1600 K.

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6 comments:

Unknown said...

is it + or - between T^3 and 9.5728....

Anonymous said...

kv = -1.1555 x 10^(-14) x T^3 9

There's a symbol missing from your formula . would you suppose I should stick in "+" or "-" between the "3" and the "9" at end of the portion I've clipped? Thanks, Dave.

Anonymous said...

-3.4007469023437027e-06 T^0
+3.4521387370766878e-08 T^1
+1.0088177790668354e-10 T^2
-1.3635276379481259e-14 T^3

T in kelvin, kinematic viscosity in square meter per second.

I'd use this equation if this link is correct:
http://www.engineeringtoolbox.com/air-absolute-kinematic-viscosity-d_601.html

Dave

Technologist said...

Yes Dear, I missed it. Its + sign between "T ^3" & "9".
Thanks for identifying the short fall.

Anonymous said...

Hi, would anyone know where I can find such a correlation but with the temperature as well with the barometric pressure or altitude effect taken into account to determine the proper dynamic viscosity.

Hugo

Anonymous said...

I just used this equation in matlab and it gave 1.5679*10^-5 for T = 295. This is off by about 20% I'd reckon. Don't use this formula.