Degradation of a seal

[Jens Eckel]

Hi all,

I started to implement the feature of degradation of a seal for a radwast repository, which we implemented years ago in TOUGH2-GRS. The degradation is mimicked by a linear change of the permeability over a given time interval.

I noticed that this could be done in PFLOTRAN by using a time dependent DATASET for the permeability, thus nothing needs to be implemented in the source code.

Unfortunately it seems that there is no change in the permeability over time with the appropriate input and h5-file (expected 2.5E-9 at t=0 d and 4.6E-9 at t=2.1E1 d ). Both files are attached, any help is appreciated.

Best, Jens   

[Hammond, Glenn E]

Jens,

 

The alteration/update of material properties has to be handled in a different manner. Either one defines a constitutive relation between the material property and state variables or a separate process model must be implemented to update the material property over time. This is somewhat implemented with the STRATA blocks that are specific to blocks of time through updates to the material IDs, but that will not help you. I recently added a parameter process model to the code. The customized parameter process model should be able to update the permeability by reading a transient dataset, though this has yet to be implemented.

 

A combination of

https://bitbucket.org/pflotran/pflotran/src/master/regression_tests/default/543/543_flow_and_tracer.in

and

https://bitbucket.org/pflotran/pflotran/src/master/regression_tests/default/parameter/3x3x3.in

are how this would be accomplished, but I admit that implementing such a capability is not easy (more at the expert PFLOTRAN developer level).

 

I need to find time/justification to implement an example….

 

Glenn

 

From: pflotr...@googlegroups.com <pflotr...@googlegroups.com> On Behalf Of Jens Eckel
Sent: Friday, March 1, 2024 4:37 AM
To: pflotran-dev <pflotr...@googlegroups.com>
Subject: [pflotran-dev: 6246] Degradation of a seal

 

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[Jens Eckel]

Hi Glenn,

thanks for your quick reply.
May be I misunderstood the description of DATASET in the online manual and especially in a SNL presentation "PFLOTRAN HDF5 Datasets" (SAND2019-2922PE). My understanding is, that for a gridded dataset, a quantity like the permeability may be given for a specific part of the grid (and may change in space) and in addition over time via the TIMES group in the hdf5 file. I do not understand why the permeability does not change over time in the input I attached to my last message.

Best, Jens

[Hammond, Glenn E]

Jens,

 

At this point in time, material properties cannot change over time (yes, there are a few caveats to that statement). The code that updates datasets for material properties has not been implemented.

 

Glenn

 

 

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[Jens Eckel]

Thank you, Glenn. I will try to understand what needs to be implemented to realize this feature. Best, Jens