Carlos Andres Rivera Villarreyes Global Product Specialist - FEFLOW

Hi nnoufysalam,

I can give some general tips for your purpose. Of course there are so many details to handle via forum.

Regarding to the concentration boundaries of river water or sea water, you need to know first the groundwater flow direction. Do you have issues of seawater intrusion? If so, it is good to prescribe a fixed concentration on these nodes. If you have outflow from the model to the river boundary all the time, concentration may not be necessarily prescribed, just leave that FEFLOW computes these values. But if you want to simulate the interaction between river and aquifer, then concentration should be prescribed in case of inflow from river to aquifer.
FEFLOW provides possibility to use the so-called constraints in order to activate or deactivate boundary conditions. I guess you can find additional info in the forum and for sure in user manual and help system.

For the case of the artificial pond, you can prescribe both water levels and concentration as Dirichlet boundary condition, if these are known.
Percolation flux from the artificial pond can be easily computed using budget panels. There is a plenty of information about this in FEFLOW User Manual and Help System.

Hope you get some idea how to start...

Cheers,

Carlos

Hi Adam,

Thanks for sending us your files. After developer checked case, he could reproduce your problem. The reason is that the FEM file was saved in ASCII format. If you save in a binary format, problem is gone.

A future version of FePEST will handle this special case, but until then please use this workaround.

Cheers,

Carlos

Hi Adam,

Thanks a lot for reporting this. Could you please send us both fem and fps files to the FEFLOW support address?

Cheers,

Carlos

In FEFLOW 6.2, there is not need to import heads from a steady-state solution to a transient model. This is done automatically when you save steady state model (after computation ends) in a new fem file. New fem file will have final results from previous run as initial conditions for next run. In three steps: [b]a)[/b] run steady-state model, [b]b)[/b] save model in a new fem file, and [b]c)[/b] advance new model to transient simulation (Problem Settings).

In case you have a transient model and you run simulation twice, now FEFLOW will ask you to modify the time-stepping control parameters (initial time and final time). Also a message will pop up stating that "[i]The simulation will be continued starting at the current simulation time[/i]".

Cheers,

Carlos

In the new FEFLOW 6.2, 3D models with an unconfined layer (Free and Movable approach) cannot support deactivation of finite elements. Since the Free-Movable approach makes a down-scaling of conductivity based on the movable slice position (avoid non-fully-saturated elements), it is not possible to offer deactivation of elements here at the moment.

Recently-released FEFLOW 6.2 includes FePEST, a convenient graphical user interface for using PEST with FEFLOW models. One important capability of this new FePEST is the so-called [b]IFM-Implemented functionality[/b]. Although FePEST includes most relevant FEFLOW parameter types and observation types for being associated with PEST, the IFM-implemented functionality provides an additional range of possibilities. Clearly, the operation of this functionality requires certain knowledge of IFM Programming in FEFLOW.

The intention of this post is to provide a general overview of the workflow. In this simple example, a plug-in computes first the depth to groundwater in the form of [b]user nodal distribution[/b] in FEFLOW and second it writes a text file (ObsIFM.DAT) with average depth for the entire model domain. Text file contains a single row. This average depth to groundwater will be subsequently used as an observation definition in FePEST in [b]Prediction mode[/b] for the evaluation of worst-case scenario (maximum aquifer drawdown). General steps for IFM-implemented observations are described below. Notice that these steps may vary depending on information retrieved with IFM plug-in.

1) IFM plug-in should be loaded and attached to the FEFLOW fem file for later used in FePEST.

2) Create a new FePEST problem (see help system for further information) and define parameters and observations (normal workflow).

3) Define a new observation definition using [b]#IFM-Implemented#[/b] as entries for both [b]definition[/b] and [b]source[/b].

4) Save the FePEST problem and create three PEST main files (and pilot point files, if needed) with [b]CHECK[/b] routine button and/or [b]RUN[/b] button in FePEST. Notice that a name of IFM-implemented observation is required. This name will appear in the PEST Instruction file (*.INS) and follows same regulations than PEST classical run.

5) Until here, FePEST creates all needed information. This can be reviewed any time from the work directory (menu [b]Estimation – Open work folder in explorer[/b] in FePEST).

By default, FePEST cites [b]IFM-implemented observation[/b] in the INS file, together with all other observations defined (e.g. hydraulic head, temperature, concentration, groundwater age, etc. specified in observation points). Therefore, IFM plug-in should be also able to write other observations in its output file when FEFLOW runs. Otherwise, it is highly recommended to create a second INS file containing only IFM-implemented observation (this option is explained below).

6) Open PST file from FePEST working directory and modify [b]NINSFILE[/b] variable. This is placed by default in [color=red][b]Line 5 and Column 3[/b][/color]. [b]NINSFILE[/b] refers to the number of INS files used in the PEST problem.

7) In the PST file, go to section [b]model input/output[/b], here the link between PEST Instruction file (*.INS) and results written by IFM Plug-in should be indicated. Write a new third row, e.g. [b]“ifm.ins” “ObsIFM.dat”[/b], where file named ifm.ins should contain as many rows as IFM-implemented observations. Make sure that output file from IFM plug-in should be written in FePEST work folder; otherwise full file path should be indicated in this section.

8) In FePEST, click on [b]Open work folder in console window[/b] from Estimation menu.

9) Run check routine for PEST control file: [b]pestchek fepest_name.pst[/b].

10) If errors are not found in item 9, run FePEST (or PEST from console window with [b]run_pest.bat[/b]).

The IFM-Implemented functionality in FePEST is a convenient manner to get access and use FEFLOW User Data in PEST optimization problems.


Carlos Rivera