Initial conditions from geometry/PoreSpy and some minor bug fixes

[alexgigliotti]

Here is a new and exciting update! Here are the main changes:

1) You can now initialize a simulation with fluid labels in a raw image. Voxels labeled 0 will be initialized as Fluid 2 (wetting phase) and voxels labeled 3 will be initialized as Fluid 1 (non-wetting phase). Voxels labeled 1 will be grains. We skip 2 because that label is reserved internally for splitting grains between surface (1) and internal (2). To use this, set fluid init: in the inputs file to "geom".

2) Because of the above, it is now possible to use a PoreSpy drainage simulation to create initial conditions for LBM simulations. This can be very useful for getting initial conditions for steady state simulations and can reduce simulation run time! Check out the new steady state relative permeability example.

• Note: A good way to check for proper domain orientation is to visualize your geometry with Vedo. The inlet will be in the YZ plane and flow is in the positive X direction; this is the same for the PoreSpy drainage and Palabos as well.

3) The capillary number is now calculated and displayed in 2-phase simulation output. You can use this to adjust forces or pressures as needed.

4) A few minor bug fixes (reloading sim state saved during run 0, i/o file closing, variable names)

[jgostick]

This warms my heart! I'm so glad it worked for you.