14 Analysis

Solver, time, and dimension

14.1 What this setting is

Analysis settings are the starting point for deciding which equations a case solves and how. Solver, steady or unsteady state, and 2D or 3D determine the available model and numerical-method options. They do not define fluid properties or boundary conditions; those are connected in separate settings later.

14.2 Configure in the GUI

Wake CFD Desktop Analysis dialog with Steady, DBNS density-based solver, and 3D selected — Figure 14.1: The Analysis dialog selects steady or unsteady time, the solver family, and the mesh dimension.

GUI control	Input key	What to choose
Solver	`analysis.solver`	DBNS is selectable in the Desktop. PBNS and FR are listed but disabled; configure those paths in JSONC.
Time	`analysis.time`	Steady or unsteady analysis.
Dimension	`analysis.dimension`	2D or 3D, matching the mesh and solver executable.

analysis selects the case’s analysis axes. Numerical options belong in numerical_method; run-time settings belong in run_control. The first imported mesh sets the initial Dimension choice; you can change it in Analysis afterward. analysis.nondimensional is not exposed in this dialog, but remains available in JSONC.

Each key is covered in its own section below.

14.3 solver

Value	Meaning	Conditions
`dbns`	Density-based finite-volume solver	Default; selectable in the Desktop
`pbns`	Pressure-based finite-volume solver	3D only; JSONC configuration
`fr`	Flux-reconstruction solver	Unsteady path; JSONC configuration and an FR-enabled build

The solver value determines the active numerical_method subblock.

dbns → numerical_method.dbns
pbns → numerical_method.pbns
fr   → numerical_method.fr

fvm and finite_volume are accepted aliases for dbns; flux_reconstruction is an alias for fr. Use canonical values in new files.

Important

analysis.discretization is not a current input key. Express FVM or FR selection with analysis.solver.

14.4 time

Value	Meaning
`steady`	Steady analysis
`unsteady`	Unsteady analysis; configure time stepping in `run_control`

DBNS and PBNS support both values. FR uses the unsteady path; selecting steady with FR produces a validation warning. Set analysis.time to unsteady for FR cases and configure their time stepping in run_control.

14.5 dimension

Value	Executable
`2`	`wake_2d_<tier>`
`3`	`wake_3d_<tier>`

The compiled WAKE_DIM must match the input value. <tier> is the precision build (fp64, mixed, or fp32); Windows executable names add .exe. PBNS currently requires 3D.

14.6 nondimensional

Value	Default / availability	Meaning
`true`	Default for DBNS; rejected for PBNS and FR.	Solve the DBNS equations in internally scaled variables.
`false`	Default for PBNS and FR; also accepted for DBNS.	Use dimensional solution variables.

This is an internal solver-variable scaling choice, not a change to the physical units requested for case inputs. It is normally best to omit the key and use the solver-specific default.

14.7 JSONC examples

The GUI writes these same keys for the DBNS choices it exposes. For the CLI, or for PBNS and FR, set them in JSONC. A steady 3D DBNS selection is:

{ "analysis": { "solver": "dbns", "time": "steady", "dimension": 3 } }

A 3D pressure-based selection is:

{ "analysis": { "solver": "pbns", "time": "steady", "dimension": 3 } }

An unsteady FR selection is:

{ "analysis": { "solver": "fr", "time": "unsteady", "dimension": 3 } }

These are analysis fragments, not complete runnable cases. PBNS and FR also need solver-appropriate models, numerical methods, and run-control settings.