Transport of Concentrated Species (tcs)
Now set up the mass transfer in the column.
1
In the Model Builder window, under Component 2  click the Transport of Concentrated Species (tcs)  interface.
2
In the Settings window for Transport of Concentrated Species (tcs) , locate the Species section.
3
From the From mass constraint list, choose wW.
Transport Properties 1
1
Expand Transport of Concentrated Species (tcs)  and click Transport Properties 1 .
2
In the Settings window for Transport Properties, locate the Model Input section.
3
Click Go to Source  for Absolute pressure. Locate the Browse Model Inputs section, in the p text field for Pressure, type P.
4
Next, choose Temperature (minput.T), and in the T text field, type T.
5
In the Model Builder tree, click Transport Properties 1 under Transport of Concentrated Species (tcs). Locate the Density section. From the list for mixture density, choose Ideal gas.
Note, if instead the Density (chem) is selected, the density will be defined by the thermodynamic system. Since ideal gas is used for the gas phase this is equivalent to the current setting.
6
Locate the Convection section. Specify the u vector as uV in the x direction.
7
Locate the Diffusion section. Select User defined and apply a negligibly small diffusion coefficient, 1e-20, for the ethanol–water pair.
Initial Values 1
1
In the Model Builder window, under Component 2 (comp2)  > Transport of Concentrated Species (tcs)  click Initial Values 1 .
2
In the Settings window for Initial Values, locate the Initial Values section.
3
In the ω0,wE text field, type wf.
Mass transfer between the phases is defined by the overall gas phase mass transfer coefficients Kya, and the local mole fraction difference from equilibrium.
Reaction Sources 1
1
In the Model Builder window, click Reaction Sources 1  under Component 2 (comp2)  > Transport of Concentrated Species (tcs) .
2
From the RwE list, choose User defined. Type -tcs.M_wE*Kya*(ym1-ye1)
in the associated text field.
3
From the RwW list, choose User defined. Type tcs.M_wW*Kya*(ym1-ye1)
in the associated text field.
Specify the bottoms ethanol mass fraction as a boundary condition.
Mass Fraction 1
1
In the Physics toolbar, click Boundaries  and choose Mass Fraction .
2
Select Boundary 1 only (the point furthest to the left).
3
In the Settings window for Mass Fraction, locate the Mass Fraction section.
4
Select the Species wE checkbox.
5
In the ω0,wE text field, type wb.
Outflow 1
1
In the Physics toolbar, click Boundaries  and choose Outflow .
2
Select Boundary 3 only (the point furthest to the right).