Dear GWB team, I would like to share with you our results of transprt modelling, which are hard for me to explain. I do not know if I do something wrongly or if there i some other mistake or problem.
I wanted to calculate the sorption filter 100x100x200 cm filled by sawdust. Sorbed substance is naphthalene. A attach script, compressed thermodataset (extended by naphthalene by us), dataset with langmuir data and two figures - outputs from calculation including my drawing. Thus, you can look directly at the results and if you would like to, also re-calculate our task.
Let describe the problem. Looking on the Figure 1 (concentration profile of naphthalene within the layer during the time): my opinion is that shape of the last two curves (right side) should be as I marked it by blue dots. Simply, the shape of the curves should not substantially change except its termination with the end of the layer. I see no reason why the curves should change their shape at the end of the layer, especially when boundary condition is set on "outlet" on the right side. Looking on the figure 2 (concentrations of naphthalene in various positions at the layer during the time): again the shape of the breakthrough curve (in the last node - last curve on right side) differs from shape of other curves. Why? It is obvious that the sheerer shape of the curve starts just at the end of the layer (it is clear also from the figure 1 - if we think about it). It seems, that there is other source of adsorbate at the end of layer, but boundary condition is "outlet" - it should be ok. Furthermore, the breakthrough curve (right curve in the figure 2) is "unreal". Its shape should be similar to for example first two curves in the same figure. I was playing a lot with this, but I can not explain it and I have no idea what to do with this problem. Finally, I found similar problem also in frame of other sorption calculations (advanced sorption modelling), I added these results because they are simplest for disclosing here. I would be very glad to have an advice what is wrong. I really think that shapes of curves are incorrect, but if you explained me if its correct, I will be glad. Thank you!
Marek Svab, Dekonta,a.s.
thermo.com.v8.r6__MS_KS_PRB_v2.zip
sorption_example_svab.x1t
Langmuir_piliny.zip