functionmixtureViscosityChung
Extends from Modelica.Icons.Function (Icon for functions).
Information
Equation to estimate the viscosity of gas mixtures at low pressures.
It is a simplification of an extension of the rigorous kinetic theory
of Chapman and Enskog to determine the viscosity of multicomponent
mixtures, at low pressures and with a factor to correct for molecule
shape and polarity.
The input argument Kappa is a special correction for highly polar substances such as
alcohols and acids.
Values of kappa for a few such materials:
| Compound | Kappa | Compound | Kappa |
|---|---|---|---|
| Methanol | 0.215 | n-Pentanol | 0.122 |
| Ethanol | 0.175 | n-Hexanol | 0.114 |
| n-Propanol | 0.143 | n-Heptanol | 0.109 |
| i-Propanol | 0.143 | Acetic Acid | 0.0916 |
| n-Butanol | 0.132 | Water | 0.076 |
| i-Butanol | 0.132 |
Chung, et al. (1984) suggest that for other alcohols not shown in the
table:
kappa = 0.0682 + 4.704*[(number of -OH
groups)]/[molecular weight]
S.I. units relation for the debyes:
1 debye = 3.162e-25 (J.m^3)^(1/2)
References
[1] THE PROPERTIES OF GASES AND LIQUIDS, Fifth Edition,
Bruce E. Poling, John M.
Prausnitz, John P. O'Connell.
[2] Chung, T.-H., M. Ajlan, L. L. Lee, and K. E. Starling: Ind. Eng.
Chem. Res., 27: 671 (1988).
[3] Chung, T.-H., L. L. Lee, and K. E. Starling; Ing. Eng. Chem.
Fundam., 23: 3 ()1984).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | T | Temperature | |
| Temperature | Tc | Critical temperatures | |
| MolarVolume | Vcrit | Critical volumes (m3/mol) | |
| Real | w | Acentric factors | |
| Real | mu | Dipole moments (debyes) | |
| MolarMass | MolecularWeights | Molecular weights (kg/mol) | |
| MoleFraction | y | Molar Fractions | |
| Real | kappa | zeros(nX) | Association Factors |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| DynamicViscosity | etaMixture | Mixture viscosity (Pa.s) |