How to reduce the computation time for coupled HM flow in disk-shape fractures

3DEC
1

Hi,

I’m working with printed 3D samples with disk-shape fractures inside and try to replicate my permeability tests with different gradients and confining stress with 3DEC.

To restrict the flow only inside the disks, I use the strategy of the example, give a big cohesion and tension outside.

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Activate the flow inside the disks

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With flow only analysis, with 10-20 minutes I have my flow rate that I compare with my results, but when I try the coupled analysis, the time is like 4 days (if the software doesn’t crash earlier).

There’s a way to cut the time, like only compute the flow in the range of the disks?

Put some code to restrict the flow inside the disks with a range command or with the geometry of the dfn?

Here an image of a flow only analysis to understaind the geometry.

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When my fractures are rectangular the computing time is not a problem its around 10-30 minutes.

Thanks for your help

2

If it’s slow in couped mode, it is probably because the factures are opening up, causing the timestep to be reduced. The easiest solution is to limit the maximum aperture. See other tips here. If you run it implicitly, you can also get a significant speed up (see [here])