Solvers

Poromics provides three solvers for estimating transport properties of porous media. Each solver page below describes the governing physics, boundary conditions, usage, and output fields.

Solver	Property	Method	Backend
tortuosity_fd	Tortuosity / \(D_\text{eff}\)	Finite differences (Krylov)	Julia
tortuosity_lbm	Tortuosity / \(D_\text{eff}\)	Lattice Boltzmann (D3Q7 BGK)	Taichi
permeability_lbm	Permeability	Lattice Boltzmann (D3Q19 MRT)	Taichi

Choosing a solver

For tortuosity, both solvers compute the same quantity — the ratio of the bulk diffusivity to the effective diffusivity through the pore space. The FD solver is generally faster for a single evaluation and supports spatially variable diffusivity fields. The LBM solver accepts physical units directly and provides the transient concentration field.

For permeability, only the LBM solver is available. It solves creeping (Stokes) flow and extracts permeability via Darcy's law.

All solvers automatically trim non-percolating pore regions before running, so dead-end pores that don't connect inlet to outlet are excluded.