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D_12_liquid
D_12_liquid(T, v_c1,v_c2, sigma_1, sigma_2, vis_2) provides an estimate of the diffusion coefficient of species 1 (solute) in species 2 (solvent) at infinite dilution using a modification of the Tyn and Calus method described in Poling et al., Properties of Gases and Liquids, 5th edition, McGraw-Hill, 2000.
Inputs:
T - temperature in the units specified in the EES unit system dialog
v_c1 and v_c2 critical volume of species 1 and 2 in units in either m^3/kmol (SI) or ft^3/lbmol (English) units
sigma_1 and sigma_2 are the surface tensions of species 1 and 2 in any consistent units, e.g, N/m.
vis_2 is the viscosity of the solvent (liquid) at T in units of kg/m-s (for SI) or lbm/ft-hr (for English) units
Output:
D_12_liquid is returned in units of m^2/s (for SI) or ft^2/s for English units.
Example:
"Determine the diffusion coefficient for methane in water at 20 C"
$unitSystem SI C kPa molar
$Varinfo T units=C
$Varinfo P_atm units=kPa
$Varinfo v_c1 units=m^3/kmol
$Varinfo v_c2 units=m^3/kmol
$VarInfo T_b1 units=C
$VarInfo T_b2 units=C
$VarINfo sigma_1 units=N/m
$VarINfo sigma_2 units=N/m
$VarINfo vis_2 units=kg/m-s
$VarInfo D units=m^2/s
G1$='methane'
G2$='water'
T=20 [C]
v_c1=v_crit(G1$)
v_c2=v_crit(G2$)
P_atm=Po#
T_b1=t_sat(G1$,P=P_atm)
T_b2=t_sat(G2$,P=P_atm)
sigma_1=surfacetension(G1$,T=T_b1)
sigma_2=surfacetension(G2$,T=T_b2)
vis_2=viscosity(G2$,T=T,x=0)
D=d_12_liquid(T, v_c1,v_c2,sigma_1,sigma_2,vis_2)
{Solution:
D=1.543E-09
G1$='methane'
G2$='water'
P_atm=101.3 [kPa]
sigma_1=0.01338 [N/m]
sigma_2=0.05891 [N/m]
T=20 [C]
T_b1=-161.5 [C]
T_b2=99.97 [C]
vis_2=0.001002 [kg/m-s]
v_c1=0.09863 [m^3/kmol]
v_c2=0.05595 [m^3/kmol]
}
This function was named d_12|o_liquid in previous versions. This name can still be used for backward compatibility.