ThermalBC Properties

(To be removed) Boundary condition for thermal model

ThermalBC will be removed. Use the EdgeBC and FaceBC properties of femodel instead. (since R2023a) For more information on updating your code, see Version History.

A ThermalBC object specifies the type of PDE boundary condition on a set of geometry boundaries. A ThermalModel object contains a vector of ThermalBC objects in its BoundaryConditions.ThermalBCAssignments property.

Specify boundary conditions for your model using the thermalBC function.

Properties

RegionType — Geometric region type

'Face' for 3-D geometry | 'Edge' for 2-D geometry

Geometric region type, specified as 'Face' for 3-D geometry or 'Edge' for 2-D geometry.

Data Types: char | string

RegionID — Geometric region ID

vector of positive integers

Geometric region ID, specified as a vector of positive integers. Find the region IDs by using pdegplot with the 'FaceLabels' (3-D) or 'EdgeLabels' (2-D) value set to 'on'.

Data Types: double

Temperature — Temperature boundary condition

number | function handle

Temperature boundary condition, specified as a number or a function handle. Use a function handle to specify spatially or temporally varying temperature.

Data Types: double | function_handle

HeatFlux — Heat flux boundary condition

number | function handle

Heat flux boundary condition, specified as a number or a function handle. Use a function handle to specify a spatially or temporally varying heat flux or a nonlinear heat flux.

Data Types: double | function_handle

ConvectionCoefficient — Coefficient for convection to ambient heat transfer condition

number | function handle

Convection to ambient boundary condition, specified as a number or a function handle. Use a function handle to specify a spatially or temporally varying convection coefficient or a nonlinear convection coefficient. Specify ambient temperature using the AmbientTemperature argument.

Data Types: double | function_handle

Emissivity — Radiation emissivity coefficient

number in the range (0,1)

Radiation emissivity coefficient, specified as a number in the range (0,1). Use a function handle to specify spatially or temporally varying emissivity or nonlinear emissivity. Specify ambient temperature using the AmbientTemperature argument and the Stefan-Boltzmann constant using the thermal model properties.

Data Types: double | function_handle

AmbientTemperature — Ambient temperature

number

Ambient temperature, specified as a number. The ambient temperature value is required for specifying convection and radiation boundary conditions.

Data Types: double

Vectorized — Vectorized function evaluation

'off' (default) | 'on'

Vectorized function evaluation, specified as 'on' or 'off'. This evaluation applies when you pass a function handle as an argument. To save time in function handle evaluation, specify 'on', assuming that your function handle computes in a vectorized fashion. See Vectorization. For details of this evaluation, see Nonconstant Boundary Conditions.

Data Types: char | string

Label — Label for use with linearizeInput

character vector | string

Label for use with linearizeInput, specified as a character vector or a string.

Data Types: char | string

Version History

Introduced in R2017a

R2025a: To be removed

ThermalBC will be removed. Use the EdgeBC and FaceBC properties of femodel instead.

For example, you can check the boundary condition on edges of the unit square as follows.

model = femodel(AnalysisType="thermalSteady", ...
                Geometry=@squareg);
model.EdgeBC([1 3]) = edgeBC(Temperature=25);
model.EdgeBC

The unified finite element model workflow defines the type of a problem and all of its parameters as the properties of an femodel object. This object enables you to specify physical parameters for structural, thermal, and electromagnetic types of analyses. The solver in the unified workflow uses only the parameters (properties) appropriate for the current analysis type while ignoring all other properties. If you switch the analysis type by setting the AnalysisType property of the model, the solver uses the appropriate set of properties corresponding to the new analysis type.

For more help migrating your existing code that uses ThermalModel to the unified finite element workflow, see Migration from Domain-Specific to Unified Workflow.