Pfc Fluid Coupling

PFC Fluid Coupling

Use this skill to explain, adapt, or generate PFC 6.0 fluid-solid coupling workflows. The skill is self-contained: baseline .dat and Python coupling examples are stored under scripts/canonical/.

Parent Skill Relationship

pfc-fluid-coupling is a child skill of pfc-workflow. It does not own the full PFC lifecycle. Use it for fluid-coupling scenario selection, CFD/buoyancy command patterns, auxiliary mesh/data contracts, and seepage-coupling handoff. Return to pfc-workflow for full case planning, solve orchestration, post-processing routing, verification, and delivery.

Parent/child split:

• Parent pfc-workflow: owns complete PFC project lifecycle and decides when fluid-coupling support is needed.
• Child pfc-fluid-coupling: owns seepage, buoyancy, CFD element setup, FiPy/Darcy coupling notes, and fluid-related input/output contracts.
• Sibling child pfc-standard-tests: owns standard mechanical-test templates and stage normalization.
• Sibling child pfc-servo-calibration: owns servo control and manual calibration sequencing.
• Sibling child pfc-postprocessing: owns standard figures and field exports after solve.
• Sibling child pfc-ae-energy: owns AE, energy, and source-mechanism outputs after solve.

When To Use

Use through pfc-workflow when a task involves fluid or pore-pressure effects:

• Explain PFC model configure cfd, CFD element input, buoyancy, or drag-coupling concepts.
• Set up simple particle-water buoyancy or particle falling-in-water examples.
• Document auxiliary input files such as CFD node/element tables.
• Adapt a Darcy/FiPy coupling script that updates PFC CFD fields.
• Decide which parts of a seepage workflow can be bundled and which remain external dependencies.

Required Inputs

Ask for these if missing:

• PFC version and dimensionality: PFC2D/PFC3D, preferably PFC 6.0 unless stated otherwise.
• Coupling scenario: buoyancy only, built-in CFD elements, Darcy/FiPy update, seepage force, drag, or pore pressure.
• Particle model: specimen geometry, particle size range, porosity, density, and boundaries.
• Fluid model: density, viscosity, velocity/pressure boundary conditions, inlet/outlet definitions.
• Auxiliary files: mesh nodes, elements, particle template, or Python coupling script.
• Required outputs: particle trajectories, force histories, pressure/velocity fields, porosity/permeability, or coupled response curves.

Canonical Template Map

Coupling Checklist

Use this checklist before writing or changing fluid-coupled logic:

1. Confirm whether the task needs simple buoyancy, built-in CFD elements, or external Darcy/FiPy coupling.
2. Confirm units for particle geometry, fluid density, viscosity, pressure, and velocity.
3. Confirm mesh input files and their coordinate scale if using cfd read nodes/elements.
4. Initialize model configure cfd before CFD element commands.
5. Define particle density/damping/contact model separately from fluid fields.
6. Define inlet/outlet or pressure/velocity boundary conditions explicitly.
7. Decide update interval for fluid recalculation relative to mechanical cycles.
8. Export enough data to reproduce coupled fields without GUI-only steps.

Working Rules

• Prefer PFC 6.0-compatible syntax unless the user explicitly targets another version.
• Treat files in scripts/canonical/ as reference templates, not final calibrated models.
• Keep auxiliary file contracts explicit: node table, element table, particle setup, Python coupling script, and generated outputs.
• Do not make helper executables the only core workflow path; place legacy apps under scripts/apps/<app-name>/, document their inputs/outputs, and keep transparent .dat/Python alternatives when possible.
• State optional Python dependencies such as numpy and fipy when using dll.py-style coupling.
• If the task becomes a full model run or validation study, hand control back to pfc-workflow.

Output Contract

A complete child-skill handoff back to pfc-workflow should include:

• The selected fluid-coupling pattern and why it fits.
• Required files or snippets from scripts/canonical/<case>/.
• Fluid assumptions: density, viscosity, boundary conditions, flow direction, and update interval.
• Auxiliary input contract: node/element/particle file schema and expected location.
• Histories or exports needed to validate the coupled response.
• Dependency warnings such as model configure cfd, FiPy availability, and mesh scale.
• A clear note that full case execution, post-processing routing, V&V, and delivery continue in pfc-workflow.

Local Contents

• references/overview.md: detailed self-contained fluid-coupling boundaries and source map.
• examples/README.md: how to validate bundled fluid-coupling demonstrations.
• scripts/canonical/: fluid-coupling demonstration code and auxiliary mesh/data files.
• scripts/apps/create_mesh/: optional mesh-helper application preserved with the fluid-coupling example set.
• scripts/canonical/manifest.json: file inventory with sizes and SHA-256 hashes.
• scripts/README.md: helper-script policy and future maintenance guidance.