Water content units out of range

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gmart
Posts: 4
Joined: Fri Jul 08, 2011 2:35 pm

Water content units out of range

Post by gmart » Sun Feb 28, 2021 8:33 pm

Hello,

Any clues on why we are getting water content values out of the range defined by the water retention curve. This is a simple representation of a 1D column based on test1. At the beginning I thought it could be an issue with the interpolation tables. Pressure heads seem in range, however water content is greater than 1. I am attaching water content, heads and soil hydraulic properties for a vertical cross section. We tried multiple boundary conditions and material properties. We also resent initial conditions a couple of times.

Thank you,

Guillermo
Attachments
2021-02-28 14_26_37-_water_content.png
2021-02-28 14_26_37-_water_content.png (10.37 KiB) Viewed 1012 times
2021-02-28 14_26_37-_pressure_head.png
2021-02-28 14_26_37-_pressure_head.png (15.44 KiB) Viewed 1012 times
2021-02-28 14_26_05-Soil Hydraulic Properties.png
2021-02-28 14_26_05-Soil Hydraulic Properties.png (22.82 KiB) Viewed 1013 times
Last edited by gmart on Sun Feb 28, 2021 8:36 pm, edited 1 time in total.

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water content units out of range

Post by Jirka » Sun Feb 28, 2021 11:04 pm

This is obviously unrealistic and unreasonable. I can imagine only one way of getting these unreasonable results: specifying the water content scaling factors (which multiply the water content) (significantly) larger than 1. If this is not the reason, then post your project here so we can review it. J.

gmart
Posts: 4
Joined: Fri Jul 08, 2011 2:35 pm

Re: Water content units out of range

Post by gmart » Mon Mar 01, 2021 4:59 pm

Thank you Jirka! Yes, I was feeling it was something related to units/scale and the GUI. I solved it right the way after your prompt advise. Have a nice rest of the week! I guess the scaling only works for display as the runs were able to converge.

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water content units out of range

Post by Jirka » Mon Mar 01, 2021 7:09 pm

This does not have anything to do with the GUI. We do not constrain in the GUI what values the users prescribe for the scaling factors, even though they obviously have to be positive and should not lead to the porosity value being larger than zero. While negative values would likely crash the program, the program has no problem with unrealistically large positive values. While physically, porosity cannot be larger than one, numerically, that is not a problem (see the Richards equation). J.

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