The modeling workflow

Every model goes through the same stages, in the order of the Model Builder tree. Each stage has its own ribbon tab and its own page in this guide.

Stage	What you do	Guide
Definitions	Parameters, variables, functions, coupling operators.	Parameters, variables and functions
Geometry	Primitives, work planes, Booleans, transforms, imported CAD, named Box Selections.	Geometry
Selections	Choose the domains, boundaries, edges or points each feature applies to.	Selections
Materials	Library or user materials, with any property as an expression.	Materials
Physics	Physics interfaces, their domain and boundary features, multiphysics couplings.	Physics interfaces, Electrochemistry: current distribution
Mesh	Physics-controlled or user-controlled meshes, sizes, distributions, mapped meshes.	Mesh
Study	Stationary, time-dependent, eigenfrequency and frequency-domain steps, parametric sweeps, solver settings.	Studies and solving
Results	Plot groups and plots, datasets, derived values, tables, export.	Results

Stage

What you do

Guide

Definitions

Parameters, variables, functions, coupling operators.

Geometry

Primitives, work planes, Booleans, transforms, imported CAD, named Box Selections.

Selections

Choose the domains, boundaries, edges or points each feature applies to.

Materials

Library or user materials, with any property as an expression.

Physics

Physics interfaces, their domain and boundary features, multiphysics couplings.

Mesh

Physics-controlled or user-controlled meshes, sizes, distributions, mapped meshes.

Study

Stationary, time-dependent, eigenfrequency and frequency-domain steps, parametric sweeps, solver settings.

Results

Plot groups and plots, datasets, derived values, tables, export.

What happens when you press Compute

Elmer Studio does whatever is out of date, in this order:

Geometry. If something changed, the geometry sequence is rebuilt with the OpenCASCADE kernel of gmsh. Domains, boundaries, edges and points are numbered by position, so the numbers stay put when you edit unrelated features.
Mesh. gmsh meshes the geometry, and the mesh is written in Elmer’s native format, with the parent elements Elmer needs for boundary fluxes.
Elmer input. Materials, physics features and study steps become an Elmer solver input file (.sif). Elmer Studio chooses the Elmer solver modules and turns expressions into Elmer’s MATC language. It switches solvers to nonlinear iteration when a property depends on the solution.
Solve. ElmerSolver runs in the background. The Progress, Log and Convergence Plot show it live. A parametric sweep runs once per parameter value.
Results. The solution is read back, and the default plots for the solved physics are created.

None of these steps needs you to look at a file. If you want to, Elmer under the hood shows where everything is.

Later features win. On a boundary selected by two boundary conditions, the lower one in the tree applies.
Default features (insulation, walls, initial values) cover everything not otherwise specified. Default boundary features apply only to exterior boundaries.
Units are welcome everywhere. 10[mm], 20[degC] and n[rpm] are converted to SI. A number without a unit is SI. Geometry is the exception: there it is in the geometry’s length unit.
Disable instead of delete (F3) to try a model without a feature.
Expressions everywhere. A material property, a boundary value or a source can depend on parameters, coordinates (x, y, z), time t, and the dependent variables.