Using extracted initial conditions in a different model

[Sami Roikonen]

Hi!

Is it possible to use initial conditions extracted from WUFI2DMotion in a different model with different geometry?

I was planning on simulating a newly cast concrete slab (100 mm x 100 mm in model, initial RH 1,0) curing for a week in stable conditions and then extracting properties from it.
Afterwards I'll use the same 5-day old concrete slab but I'll add a 30 mm floor screed on top of it. The old slab should have the extracted properties and floor screed should be fully saturated (RH 1,0). Next I'll dry the structure until at certain depth I'll have satisfactory RH, and I'll extract the initial conditions yet again.
Finally I'll add flooring on top of the screed and use the extracted initial conditions for the concrete and the screed.

Is doing this possible? I worry that changing the model's geometry will fiddle with the extracted conditions, since they are most likely bound to the grid-coordinates of the previous model.
I tried and when I first changed to model, the results were very strange. The screed had a constant RH 0,5 during the simulation. It failed completely.

Should I instead just create multiple layers of concrete and have their RH change gradually? This would be doable, but the moisture distribution in the concrete would be very distorted and total water content highly exaggerated.

Can somebody help me with this? After the weekend, of course.

-Sami

[Christian Bludau]

Hello Sami,

you can open the 2D movie and extract the conditions of you wanted time step (usually the last one) into a file. For that go to the temperature and the R.H. window, do a right click and select "extract -> initial conditions".
Then in WUFI 2D go to the initial conditions section, here you can open the files.

This will also work if you ad a layer at the right side or upper side of your construction (the positive increasing coordinates). The layers, which are not existent in your initial conditions file should get assigned the initial conditions you enter in the table.

For example:
First assembly (o is origin)
aaaaa
aaaaa
Aaaaa
o

The grid is defined starting at the A, x-direction to the right, y direction up. So if you extract the initial conditions here, you can use that with the following construction:
bbbbbb
aaaaab
aaaaab
Aaaaab
o
For the a-elements the value is coming from the chosen file, for the b-Elements from the table.
Please recheck after calculation, if the initial conditions where used correctly...

Regards,
Christian

[Sami Roikonen]

I tried using extracted initial conditions while simultaneously adding materials with different conditions. It didn't work as I hoped.
When I set the initial conditions from a file, the table is greyed out. It seems to set the conditions from the file to the whole model. As you can see from the image, the layer of screed has the same RH as the top grid layer had.

But if it takes the initial conditions from the last grid layer and applies them to the new, extended area of the model, I was thinking maybe I can edit the txt-file itself. If I add one layer with RH 100 % on top of the old grid, it should change the screed's RH to 100 % as well. This might be a bit tedious work-around for this, but for a simple test like this it should be ok.

I hope you can advise me with this!

-Sami