Chung et al. Viscosity Model

The ChungViscosityPure pure component gas dynamic viscosity model can be imported from idaes.models.properties.modular_properties.pure.

Formulation

The description of the Chung et al. model for viscosity here is derived from that in The Properties of Gases and Liquids, Section 9-4-2. Pure component gas viscosity is given by the formula:

\[\mu = C\frac{F_c \sqrt{MT}}{V_c^{2/3} \Omega_v(T)}\]

in which \(\mu\) is the dynamic viscosity, \(M\) is the molar mass, \(V_c\) is the critical molar volume, and \(\Omega_v(T)\) is a dimensionless quantity known as the collision integral. \(C\) is a constant with value \(40.785\;\mu\text{P}(\text{mL}/\text{mol})^{2/3}/\sqrt{(\text{g}/\text{mol})\text{K}}\), and

\[F_c = 1 - 0.2756 \omega + 0.059035 p_r^4 + \kappa\]

in which \(\omega\) is the acentric factor, \(p_r\) is the reduced molecular dipole moment, and \(\kappa\) is a correction factor, called the association factor, given for certain polar molecules. Values for \(\kappa\) can be found in The Properties of Gases and Liquids, Table 9-1, which in turn are taken from Chung et al. (1988). The reduced dipole moment is given by:

\[p_r = K \frac{p}{\sqrt{V_cT_c}}\]

in which \(p\) is the (dimensionful) dipole moment and \(K\) is a constant with value \(131.3\;\sqrt{(\text{g}/\text{mol})\text{K}}/\text{debye}\).

The collision integral is specific for the property of viscosity (e.g., there is a different collision integral for diffusivity calculations) and is given in terms of dimensionless temperature. For the purpose of this correlation, the dimensionless temperature used is a scaled version of the reduced temperature:

\[T^* = 1.2593\frac{T}{T_c}\]

in which \(T_c\) is the critical temperature. Callbacks for the collision integral are described here.

List of Parameters

Parameter Name	Description	Units
mw	Molecular weight \(M\)	Mass/Amount
temperature_crit	Critical Temperature \(T_c\)	Temperature
dens_mol_crit	Inverse critical molar volume \(1/V_c\)	Amount/Volume
omega	Acentric factor \(\omega\)	Dimensionless
dipole_moment	Molecular dipole moment \(p\)	Charge/Length
association_factor_chung	Association factor \(\kappa\)	Dimensionless
viscosity_collision_integral_callback	Callback to use for viscosity integral	n/a

Example

The code snippet below demonstrates how to specify use of the ChungViscosityPure model for pure component vapor viscosity as part of the modular property framework. Note that if you specify visc_d_phase_comp for one phase, you must specify it for all phases, even if only to pass None as the method.

from idaes.models.properties.modular_properties.pure import ChungViscosityPure
from idaes.models.properties.modular_properties.pure.ChapmanEnskog import collision_integral_neufeld_callback, collision_integral_kim_ross_callback

configuration = {
  "components":{
    "H2O": {
      "type": Component,
      "valid_phase_types": [PhaseType.vaporPhase, PhaseType.liquidPhase],
      ...
      "visc_d_phase_comp": {"Vap": ChungViscosityPure, "Liq": None},
      "viscosity_collision_integral_callback": collision_integral_neufeld_callback,
      "parameter_data": {
        "mw": (0.01801528, pyunits.kg / pyunits.mol),
        "temperature_crit": (647.3, pyunits.K),
        "dens_mol_crit": (0.01787, pyunits.mol/pyunits.mL),
        "omega": 0.344,
        "dipole_moment": (1.8546, pyunits.debye),
        "association_factor_chung": 0.076
      }
      ...
    }
    ...
  }
  ...
}

References

Poling, Bruce, E. et al. The Properties of Gases and Liquids. 5th ed. New York: NcGraw-Hill, 2001.

Chung, Ting Horng, et al. “Generalized multiparameter correlation for nonpolar and polar fluid transport properties.” Industrial & Engineering Chemistry Research 27.4 (1988): 671-679.