Transport model of carbonate dissolution by x2t

[Pang Yuhan]

Hellow~

I tried to build a transport model of carbonate dissolution reaction. However, the following situations were encountered during the simulation:

1.At 60% of the simulation time, the simulation interrupt caused by too large residual error occurs.

2.During the simulation, although the program is still running, the progress will not increase (Xi will not increase, but the reaction simulation is still running).

I want to know what caused these problems and how to solve them?

Thank you！

白云石溶解（裂缝）.x2t 方解石溶解（裂缝）.x2t

[Jia Wang]

Hello Yuhan,

Sorry for the delay in getting back to you. What release version of the software you are using? While it took a bit of time to complete the simulation, I did not encounter the too large residual error or the progress being stuck error. 

To start troubleshooting, I would recommend you using the the 'explain steps' and the 'Follow Output' options. By turning on 'explain steps', the GWB apps will report the limiting factor for the size of time steps over the course of the simulation (e.g. intensity of kinetic reaction, user set maximum steps, etc) . To enable 'explain steps', you can go to Config --> Stepping and select the check box for explain steps. Then to see the limiting factor reported by explain steps, make sure you also check the 'Follow Output' option on the Results pane too. You might also want to shorten your run time, maybe to just 1000 years, to check if your model is performing the calculations that you are expecting. Once you confirm that the model is setup correctly for the reactions you are expecting, then extend the simulation time to what you need. 

I also noticed that your model have a central row of nodes in which porosity is set to 1 and this might be causing issues with your simulation. Can you explain what you're trying to do in this model? Perhaps a 1D dual porosity model might suite your needs and would require less computational power than X2t. 

Hope this helps,

Jia Wang

[Pang Yuhan]

Thank you for your reply!

I use the latest version of gwb14. Set to 1 because I want to set an open crack in the center of the model.

[Pang Yuhan]

Just now, Pang Yuhan said:

Thank you for your reply!

I use the latest version of gwb14. Set to 1 because I want to set an open crack in the center of the model.

Setting to 1 may be a problem. Because in the result, I found that the porosity value will be greater than 1.