MINC interface surface area
Dear Stefan,
I have been working with MINC for some time now. Just today, I found out that the interface surface area between two adjacent cells is the same for the fracture and matrix volumes. For the same primary mesh but with different fracture volumes, the flux of gas through the fracture is approximately the same since the velocity is the same as well as the interface surface area. Looking at the mesh and connection properties, the interface area is equal to the primary mesh interface area for both the fracture and the matrix. Why is the interface surface area not adapted when applying MINC?
Thanks in advance!
Marielle
2 replies
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Marielle,
The interface area should indeed be the same for the primary and secondary meshes, as MINC is a continuum approach, i.e., you will have to provide an effective fracture permeability for the entire fracture network, which acts on the full interface area. The volume fraction only affects the volumes (i.e., the storage term). Like in a regular system (at least under steady-state conditions), the volume does not directly affect the flow (permeability and gradients do); the same is true for a MINC system.
At first glance, MINC is straightforward, but often confusing when you look at it in more detail (as you did). The two things to bear in mind is that (1) you are looking at two continua (not individual fractures), and (2) the discretization is not representing individual fractures (as the "sugar-cube" picture misleadingly suggests); it discretizes the governing continuum equations.
Hope these short comments help.
Stefan
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Hi Stefan,
Thank you for the quick response! This is very clear. The case that I try to simulate is quite complex since I do want to simulate an individual fracture. I know that MINC is not designed for this, but by adapting the mesh manually (like deleting the connections which I don't need) a lot is possible guess. I will therefore also adapt the surface areas manually.
Thanks again!
Marielle