getTwoPhaseProperty

getTwoPhaseProperty is used to retrieve two-phase mixture properties.

Syntax

[value1,value2]=getTwoPhaseProperty(propName,phaseName1,phaseName2,T,P,moleFraction1,moleFraction2)

Arguments

propName
String; name of the property. The following two phase properties may be supported, depending on the underlying thermo system. Please note that in case the material objects that represent the material streams only implement support for CAPE-OPEN version 1.0, and not for version 1.1, the support for two-phase properties will be limited. In particular, composition derivatives will not be available.

property name	description	unit of measure
kvalue	Ratio of fugacity coefficients for a pair of phases defined as follows: kvalue_i=phi_{i,phase 2}/phi_{i,phase 1}; where phi is the fugacity coefficient
kvalues	Ratio of fugacity coefficients for a pair of phases defined as follows: kvalue_i=phi_{i,phase 2}/phi_{i,phase 1}; where phi is the fugacity coefficient
logKvalue	Natural logarithm of K-value
logKvalues	Natural logarithm of K-value
surfaceTension	Interfacial tension for a pair of phases	N m

The temperature derivatives of the above properties may be obtained by adding .Dtemperature to the property name, e.g. enthalpy.Dtemperature. Pressure derivatives may be obtained by adding .Dpressure. Mole fraction derivatives may be obtained by adding .DmolFraction. Mole number derivatives - for a total of 1 mole of mixture - may be obtained by by adding .Dmoles.
Mole number and mole fraction derivatives will return two sets of data: composition derivatives w.r.t. phase 1 followed by composition derivatives w.r.t. phase 2. See getFeedProperty for comments on various kinds of enthalpy.

phaseName1
String; name of the first phase for which to retrieve the property. The defined phase names depend on the underlying thermo system.

phaseName2
String; name of the second phase for which to retrieve the property

T
Double; temperature (K) at which to retrieve the property values

P
Double; pressure (Pa) at which to retrieve the property values

moleFraction1
Double; composition of the first phase at which to retrieve the property values. This must be a vector, with the number of elements equal to the number of compounds.

moleFraction2
Double; composition of the second phase at which to retrieve the property values

Returns:

value1
Double; values for the properties. Depending on the property, this may be a scalar value (e.g. surfaceTension), a vector value (one value for each compound, e.g. kvalue), or a matrix (number of compounds squared, e.g. kvalue.Dmolfraction).
For composition derivatives, this is the derivative w.r.t. to the composition of the first phase.

value2
For composition derivatives, this is the derivative w.r.t. to the composition of the second phase. For other properties this value will be empty.

Examples

» xVap=[0.3 0.7]

xVap =

    0.3000    0.7000

» xLiq=[0.8 0.2]

xLiq =

    0.8000    0.2000

» sigma=getTwoPhaseProperty('surfaceTension','vapor','liquid',298.15,101325,xVap,xLiq)

sigma =

  9.9376e-005

» sigmadP=getTwoPhaseProperty('surfaceTension.Dpressure','vapor','liquid',298.15,101325,xVap,xLiq)

sigmadP =

     0

» [sigmadx1,sigmadx2]=getTwoPhaseProperty('surfaceTension.DmolFraction','vapor','liquid',298.15,101325,xVap,xLiq)

sigmadx1 =

     0     0


sigmadx2 =

  1.0e-003 *

    0.0000    0.4969

» %surface tension for this system does not depend on vapor composition or pressure