Draft. This manual is new and still growing. If something here does not match what you see in the software, the software is right — tell us and we will fix the page.
Concepts
The only section where explaining the physics is the job. Everywhere else the reader is assumed to be an engineer who knows what a Reynolds number is and does not know where the Refinements panel is.
These exist because each one is a decision the application asks you to make and cannot make for you.
| Page | The question it answers |
|---|---|
| Mesh independence | When is a result a result, rather than a property of the mesh |
| y+ and wall treatment | Why the first cell height decides whether the turbulence model is being used correctly |
| Choosing a turbulence model | What k-omega SST and k-epsilon are actually choosing between |
| Steady or transient | Why a steady solver on an unsteady problem plateaus forever |
| Convergence and residuals | What falling residuals do and do not prove |
| Courant number | Why the time step is not yours to choose freely |
| Verification and validation | The difference, and why the distinction is not pedantry |
The last one is worth reading first. It is the vocabulary the whole Validation section depends on, and getting a customer to use the words precisely is how the conversation about accuracy stays honest.
Suggested order
They cross-reference each other, but this is the order in which they build.
What these pages do not contain
No screenshots, by design — a concept page that goes stale with a UI change is
worse than one that sends you to the reference. Where a diagram would genuinely
help, the page carries a TODO(image) comment naming exactly what it should
show, so the gap is recorded rather than papered over.
Numbers on these pages are either conventional published ranges, named as such, or thresholds the application itself applies, named as those. Nothing here is a specification of the software's accuracy; that lives in Validation.