Source: examples/phasefield

Phase-field examples¶

The upstream examples/phasefield folder contains transient diffuse-interface problems that are not fracture-specific: Allen-Cahn, Cahn-Hilliard, and Kobayashi dendrite growth.

Files in this folder¶

allencahn-2d.json: single-order-parameter Allen-Cahn evolution with a circular nucleus.
cahnhilliard-2d.json: 2D Cahn-Hilliard spinodal-decomposition setup with random concentration initialization.
cahnhilliard-3d.json: 3D Cahn-Hilliard version of the same model.
kobayashi-dendrite.json: two-field dendrite-growth problem with order parameter eta and temperature T.

Representative input¶

cahnhilliard-2d.json shows the standard two-field setup used in this folder:

json { "dofs": { "names": ["c", "mu"] }, "elements": { "elmt1": { "type": "cahnhilliard", "dofs": ["c", "mu"], "material": { "type": "binarymixture", "parameters": { "D": 1.0e1, "chi": 2.5, "kappa": 0.005 } } } }, "ics": { "seed": { "type": "random", "dofs": ["c"], "icvalue": 0.0, "domain": ["alldomain"], "parameters": { "minval": 0.495, "maxval": 0.505 } } }, "projection": { "type": "default", "scalarmate": ["F", "dFdC", "d2FdC2"], "vectormate": ["gradc"] }, "job": { "type": "transient", "print": "dep" } }

Notes¶

allencahn-2d.json uses the DoF name "eta", the "allencahn" element, and doublewell material parameters.
cahnhilliard-*.json use the DoF names ["c","mu"], the "cahnhilliard" element, and binarymixture material parameters.
kobayashi-dendrite.json uses ["eta","T"], the "kobayashi" element, kobayashimate, and two separate initial-condition blocks.
Every file in this folder is transient and uses "timestepping":{"type":"be",...}.
Several upstream files still include "restart": true inside "job", but the current parser ignores that field.