initial condition in saturated soil column with high suction at the bottom

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Mitra
Posts: 26
Joined: Thu Dec 06, 2018 3:44 pm
Location: Switzerland

initial condition in saturated soil column with high suction at the bottom

Post by Mitra » Wed Jan 27, 2021 9:45 am

I am trying to use HYDRUS to simulate transport in soil columns that start in fully saturated condition and simultaneous with opening the bottom valve, a high level of suction is applied (-300 cm to -800 cm). Now, I would have liked to ask you 2 questions. My simulations does not even pass the first iteration.
So I wanted to check if my assumptions on the initial condition is correct? I have assumed that initial condition will be computed from hydrostatic pressure (so in a saturated soil column with 60cm length, it starts at 0 at the top and +60 at the bottom where suction will be applied); or simply 0 pressure everywhere in the domain will be enough for HYDRUS to simulate initial fully saturated condition?
Then, I am thinking how can I apply such a suction(-300 cm to -800 cm) at the bottom so the discontinuity between +60cm and -300cm at the bottom (caused by initial condition and boundary conditions) does not result in a model that is not converging.

Thanks a lot for your information.

Jirka
Posts: 5216
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: initial condition in saturated soil column with high suction at the bottom

Post by Jirka » Wed Jan 27, 2021 6:43 pm

You should keep at least one node at the top unsaturated. J.

Mitra
Posts: 26
Joined: Thu Dec 06, 2018 3:44 pm
Location: Switzerland

Re: initial condition in saturated soil column with high suction at the bottom

Post by Mitra » Thu Jan 28, 2021 1:02 pm

I think that I didn't explain myself well. If I have a 60 cm soil column that is initially fully saturated (with ponding water of 2 cm accumulated at the top), and it is exposed to a suction of -800 cm at the bottom. What should I change in the attach project (example.zip
example.zip
(11.7 KiB) Downloaded 32 times
) so I do not face "numerical model did not converge error"
Thanks a lot for your time and response.

Jirka
Posts: 5216
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: initial condition in saturated soil column with high suction at the bottom

Post by Jirka » Fri Jan 29, 2021 1:26 am

Here it is. J.
Attachments
1INFILTR.rar
(20.62 KiB) Downloaded 41 times

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