• The first step is to solve a simple "Diffusion" problem, which requires no code:

-\nabla\cdot\nabla p = 0

• Which will have a weak form of:

\left (\nabla p, \nabla \psi_i \right ) - \left < \nabla p \cdot \mathbf{n}, \psi_i \right > = 0

• For now, ignore the boundary term (set $$\nabla p \cdot \mathbf{n} = 0$$\$ )
• This is similar to the pressure equation we need for Darcy flow
• Use the Diffusion object that already exists in MOOSE (no code necessary!)
• Need to specify the geometry and set up an axisymmetric problem
• Further, define boundary conditions to impose the pressure in each tank
• All of this can be accomplished in the input file...

step1.i

# Create a Test

• Create a simple test that mimics the behavior of the problem above, but use a smaller mesh to increase the speed.

tutorials/darcy_thermo_mech/step1_diffusion/tests/bcs/diffusion/tests

tutorials/darcy_thermo_mech/step1_diffusion/tests/bcs/diffusion/diffusion.i