Hi,

I was wondering if someone knew the constant in the Sutherland's relation for Helium gas.

Thanks in advance,

Nashat

Hi Nashat,

I do not have exactly the data you ask for, but can suggest the following way to get it:

o Data for He may be found in http://properties.nist.gov/SemiProp/Gases/He.html

o Choose a reference temperature and its associated viscosity.

o Assume a value for the missing parameters, S.

o Use a least-squares curve fit to find the value of S that most closely follows the experimental data from NIST.

I hope this helps.

I found the formula for the air:

nul=1.486*10e-6*(T^1.5)/(110.6+T)

for the Helium shouldn't be far. Take a look at Schlichting or A. Walz. "Boundary Layers of flow and Temperature". M.I.T. Press. 1969

Use Lennard-Jones potentials, more data available and more accurate

Here are the constants of the Sutherland law for Helium :

mu0 = 3.93267e-5 T0 = 809 C0 = 147.2

Hope it helps someone.

Alexandre Chatelain. PhD student - LES of Heat Transfer. CEA Grenoble - LEGI/Most Team - FRANCE.

Thanks a lot for your replies. I'll give the data from NIST a try. Thanks Rami.

Nash'at