Poroelastic properties in 2D Magma Reservoir example

Internally, PyLith uses

  • General poroelasticity
    • solid density
    • fluid density
    • fluid viscosity
    • porosity
  • Isotropic linear poroelasticity
    • shear modulus
    • drained bulk modulus
    • biot coefficient
    • Biot modulus

Any extra fields in the auxiliary field are ignored. It looks like the magma-2d example and the information about the poroelasticity auxiliary field need to be updated to match the code.

Does this mean that even if I include permeability, it won’t be used when solving for the solution vector?

Sorry, I missed a couple of lines in the code. The isotropic linear poroelasticity bulk rheology includes isotropic or tensor permeability.

  • General poroelasticity
    • solid density
    • fluid density
    • fluid viscosity
    • porosity
  • Isotropic linear poroelasticity
    • shear modulus
    • drained bulk modulus
    • Biot coefficient
    • Biot modulus
    • Isotropic permeability or tensor permeability

Got it, thank you, this is very helpful!
The way the examples are set up and from what I understand, the Biot modulus M is computed from the porosity \phi, Biot coefficient \alpha, solid grain bulk modulus K_s, and fluid bulk modulus K_f specified in the .cfg as 1/M = (\alpha-\phi)/K_s+\phi/K_f. Since \alpha and M are not independent poroelastic properties, I think it would make sense to similarly compute \alpha internally from the specified K_s and K_d (instead of having to specify it) to make sure the poroelastic properties are consistent. Alternatively, K_s could be computed from the specified \alpha.