FEM Thermal Analysis
Heat transfer and thermal stress analysis
Overview
Thermal analysis predicts temperature distributions and heat flow in your design. confBuild supports three thermal analysis types, from simple steady-state to fully coupled thermo-mechanical simulations.
Steady-State
Equilibrium temperature
Transient
Time-dependent heat transfer
Thermo-Mechanical
Coupled thermal & structural
Steady-State Thermal
Computes the equilibrium temperature distribution when heat input and output are balanced. Time is not a factor.
When to Use
- Heat sink and cooling system design
- Insulation performance evaluation
- Steady operating conditions of equipment
- Thermal bridge analysis in buildings
Configuration
analysisType
thermal
Analysis type selector
thermalAmbientTemp
20
Ambient temperature (°C)
Boundary Conditions
- Temperature: Prescribe fixed temperature on surfaces (e.g., 100°C on heat source, 20°C on cold side)
- Heat Flux: Apply heat flow rate per unit area (W/m²) on surfaces
Output Fields
temperature
Temperature distribution (°C)
heat_flux_magnitude
Heat flux magnitude (W/m²)
Transient Thermal
Simulates how temperature changes over time, including heating and cooling processes.
When to Use
- Heating and cooling cycle simulation
- Thermal shock analysis
- Welding and soldering temperature profiles
- Electronic component thermal management
Configuration
analysisType
thermal_transient
Analysis type selector
thermalTransientDuration
60
Simulation duration (seconds)
thermalTransientSteps
50
Number of time steps
Material Requirements
Transient thermal analysis requires additional material properties beyond Young's modulus:
- Thermal Conductivity (k) — W/(m·K) — Rate of heat conduction
- Specific Heat (cp) — J/(kg·K) — Heat storage capacity
- Density (ρ) — kg/m³ — Required for thermal mass calculation
All 39 materials in the confBuild library include these properties.
Thermo-Mechanical Analysis
Couples thermal and structural analysis to compute thermal stresses caused by temperature gradients and constrained thermal expansion.
When to Use
- Thermal expansion stress in constrained assemblies
- Bimetallic strip and bi-material thermal effects
- Engine and turbine component thermal stress
- PCB warping under thermal cycling
Configuration
analysisType
thermo_mechanical
Analysis type selector
Requires both mechanical BCs (constraints) and thermal BCs (temperatures/heat flux).
Material Requirements
In addition to standard mechanical and thermal properties, thermo-mechanical analysis uses:
- Thermal Expansion Coefficient (α) — 1/K — Linear thermal expansion rate
Best Practices
Tips for accurate thermal simulations.
Recommendations
- For transient analysis, ensure sufficient time steps to capture temperature gradients
- Use finer mesh in regions with high thermal gradients
- Verify material thermal properties are realistic for your temperature range
- For thermo-mechanical: first run a thermal-only analysis to verify temperature distribution, then couple with structural
- Consider convection effects by applying appropriate heat transfer coefficients on exposed surfaces