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.

flowchart TD
  V["Verification and validation<br/>— the vocabulary"]
  V --> M["Mesh independence"]
  V --> C["Convergence and residuals"]
  C --> S["Steady or transient"]
  S --> K["Courant number"]
  M --> Y["y+ and wall treatment"]
  Y --> T["Choosing a turbulence model"]

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.