DHI Import

Thanks, Peter.

I tested the Unconfined-aq case with different solution convergences. With large convergence criteria, the solutions of the Unconfined aq. case were not correct. Considering the analytical solution and the Confined-aq case (see below), the modeled pumping rate might not be too big.

This modeling is for a simple pumping-well simulation:
- A single well in the homogeneous isotropic medium using a constant pumping rate.
- A steady-state analytical solution is available (Thiem-Dupuit formula, see (1)).

For your review, I have attached three files:
(1) Model setting and results - comparison between the analytical solution and the results of Confined-aquifer case. (pdf file)
(2) Model file:  Confined-aquifer case
(3) Model file:  Unconfined-aquifer case  --> the dt plot is shown in (1)

Could you review the above three files and help me understand the following?
(a) Are there some missing items/settings in the model file (2)?
(b) How to solve the convergence issue in (2)?

Best,

Hi,

I am also having a similar problem (see pictures attached)

I have set different 3r kind BC (Cauchy) in a 3D model (on the top slice and with all the nodes in the river's vicinity selected). All the condition are suposed to be an exit of the model for the water: so the in-transfer rate is set equal to 0, and the out transfer is set to a positive value.

What I find in the rate budget is that there is a very high value for both in and out rate on the Cauchy BCs bar. The difference between these values is sometimes an exit rate that I could interpret as the real water leaving the model in that area, but many other times it just doesn't make any sense... I really need to understand how much water is leaving the model to validate it.

Also, by checking the head distribution it doesn't seem that there is any place where the water is entering the model through the BC.

Thank you very much,

Guillem

Hi,

I am also having a similar problem (see pictures attached)

I have set different 3r kind BC (Cauchy) in a 3D model (on the top slice and with all the nodes in the river's vicinity selected). All the condition are suposed to be an exit of the model for the water: so the in-transfer rate is set equal to 0, and the out transfer is set to a positive value.

What I find in the rate budget is that there is a very high value for both in and out rate on the Cauchy BCs bar. The difference between these values is sometimes an exit rate that I could interpret as the real water leaving the model in that area, but many other times it just doesn't make any sense... I really need to understand how much water is leaving the model to validate it.

Also, by checking the head distribution it doesn't seem that there is any place where the water is entering the model through the BC.

Thank you very much,

Guillem

[quote author=Peter Schätzl link=topic=539.msg1289#msg1289 date=1231748717]
Using discrete elements, the fractures will be 'between' the layers (if you think about horizontal fractures). They will be reduced in the model to 2D. FEFLOW does not handle a double porosity approach, where the same layer has different properties for the fracture and matrix parts.
[/quote]

Dear Peter,

I try to model karstic area with FEFLOW. You allready wrote down that FEFLOW does not handle double porosity. I just wonder that if I enter the tabular data  for unsaturated media to represent double porosity, would't the results represent double porosed media. If I enter data in the attachment and use the spline model for unsaturated flow, does the results represent double porosed media ? Or do I have to define discrete elements for the karstic media everytime ?

[quote author=Peter Schätzl link=topic=539.msg1289#msg1289 date=1231748717]
Using discrete elements, the fractures will be 'between' the layers (if you think about horizontal fractures). They will be reduced in the model to 2D. FEFLOW does not handle a double porosity approach, where the same layer has different properties for the fracture and matrix parts.
[/quote]

Dear Peter,

I try to model karstic area with FEFLOW. You allready wrote down that FEFLOW does not handle double porosity. I just wonder that if I enter the tabular data  for unsaturated media to represent double porosity, would't the results represent double porosed media. If I enter data in the attachment and use the spline model for unsaturated flow, does the results represent double porosed media ? Or do I have to define discrete elements for the karstic media everytime ?

Hello
I have to run a 3D regional, unsaturated flow model,
The model seems to run in the begining but after one day , it take very small time steps and require an enorm disk space!!!
I note that I have assigned powerfunctions of rivers in my model from 1 day to  397 days.
When I have run, feflow calculates 50 days in 15 hours (enorm time of simulation) knowing that the final time is 397 days!!!!
Can you please tell me how to do to run it correctly,
I have take default settings as said in the help to guarantee a stable simulation run.
Thank you very much for any help.

Hello
I have to run a 3D regional, unsaturated flow model,
The model seems to run in the begining but after one day , it take very small time steps and require an enorm disk space!!!
I note that I have assigned powerfunctions of rivers in my model from 1 day to  397 days.
When I have run, feflow calculates 50 days in 15 hours (enorm time of simulation) knowing that the final time is 397 days!!!!
Can you please tell me how to do to run it correctly,
I have take default settings as said in the help to guarantee a stable simulation run.
Thank you very much for any help.

All threads from the FEFLOW Newsgroup have now been moved to a new board. The newsgroup will no longer be available.

Hi Dwaine,

yes, we had a good trip to California and DC, and back home.

The icons and speed problems with the forum have been fixed now. Thanks again for letting me know.

I'll move the topics from the newsgroup ASAP (probably next week), maybe into a new board to separate them from new posts.

Peter

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