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Temperature Constraint

In one sentence: Fix the temperature on selected faces, edges, or vertices to a prescribed value — the Dirichlet thermal boundary condition.

Overview

Workbench: FEM
Menu: FEM → Model → Thermal BCs → Temperature Constraint

Fixes the temperature on selected geometry to a prescribed value. This is the thermal equivalent of the Fixed Constraint in structural analysis — it anchors the temperature field.

When to use it

  • Face cooled by a heat sink held at a known temperature.
  • Face in contact with a constant-temperature reservoir (isothermal wall).
  • Every thermal analysis must include at least one Temperature Constraint to anchor the temperature scale.

Parameters

Parameter Description
Temperature Prescribed temperature (°C or K)
References Face(s), edge(s), or vertex/vertices

Common mistakes and pitfalls

Missing temperature constraint → singular system

A thermal analysis with only heat flux loads (no Temperature Constraint) produces an undefined temperature field. Always include at least one Temperature Constraint.

Python API

import ObjectsFem
doc = App.ActiveDocument
analysis = doc.getObject("Analysis")

temp_bc = ObjectsFem.makeConstraintTemperature(doc, "TempBC")
temp_bc.Temperature = 20.0  # °C
temp_bc.References = [(doc.getObject("Body"), "Face1")]
analysis.addObject(temp_bc)
doc.recompute()

See also