OpenFOAM fvSolution Helper

When to use this OpenFOAM helper

• Use it when creating a basic fvSolution for simpleFoam-like, pisoFoam-like, or pimpleFoam-like starter cases.
• Use it when convergence problems suggest solver tolerances or relaxation factors need review.
• Use it before residual-log analysis so expected residualControl choices are visible.

How to use

1. Select the solver family, distribution guidance, and relevant case settings.
2. Enter only small dictionary, log, folder-listing, or scalar inputs needed by the helper.
3. Click the explicit action button; default values and typing alone do not generate output.
4. Review warnings, compatibility notes, output text, visual summary, and human-review checklist before copying or downloading.

Input guide

Solver family

Maps to SIMPLE, PISO, or PIMPLE starter sections.

Linear solvers

Pressure and velocity solver choices are written into the solvers subdictionary.

Tolerances

Positive tolerance and non-negative relTol values control linear solve stopping.

Correctors

Corrector counts are non-negative integers and appear in the selected coupling block.

Relaxation

Relaxation factors must be in the interval (0, 1].

Notation

Output explanation

• The output is editable fvSolution text targeted to system/fvSolution.
• The visual summarizes corrector counts and relaxation factors.
• Warnings explain field-name and solver-family review needs.

Supported OpenFOAM patterns

• SIMPLE, PISO, and PIMPLE starter sections
• PCG, GAMG, smoothSolver, and PBiCGStab text settings
• basic residualControl snippets for p and U

Unsupported patterns

• multi-region solver dictionaries
• complete preconditioner tuning
• field-specific advanced solver controls
• automatic convergence certification

Output interpretation

• fvSolution controls linear solvers and coupling algorithms; poor settings can slow or destabilize convergence.
• Relaxation values damp updates but cannot fix wrong physics, mesh quality, or boundary conditions.

Practical review guidance

• Use residual logs to review whether tolerance and relaxation changes helped.
• Keep pressure and velocity tolerances consistent with solver recommendations.

Worked examples

Assumptions

• Inputs are interpreted as plain text or scalar numbers supplied by the user.
• Generated OpenFOAM text is starter guidance, not proof of solver compatibility.
• The installed OpenFOAM distribution and case physics remain the final authority.
• p and U are the main pressure and velocity field names.

Practical guidance

• If residuals oscillate, review boundary conditions and schemes before only tightening tolerances.
• Use lower relaxation factors cautiously; they can improve robustness but slow convergence.

Common mistakes

• Using relaxation factors greater than 1.
• Setting relTol to zero without understanding cost.
• Choosing a coupling block that does not match the solver.
• Assuming low residuals prove physical correctness.

Limitations

• The helper does not tune multigrid levels, preconditioners, smoothers, or distribution-specific advanced options.
• The tool does not run OpenFOAM, check syntax with OpenFOAM utilities, or inspect local case folders.
• Distribution-specific dictionary differences may require edits before use.
• Critical engineering work requires validated solver workflows and qualified professional review.

Related workflow links